The problem the EPFL researchers, led by Mikael Reichler, Simone Bianconi and Tobias Kippenberg, set out to solve is rooted in the physics of optical feedback. In a conventional self-injection-locked system, a distributed-feedback (DFB) diode is coupled to a silicon nitride microresonator whose resonances act like an extremely selective mirror. Light reflected from the resonator pulls the laser frequency toward the resonance, and the laser’s noise collapses. But two conditions must be satisfied simultaneously: the free-running laser frequency must sit close enough to a cavity resonance, and the phase of the back-reflected light must fall within a narrow window. Temperature drifts, fabrication tolerances and the natural tuning of the laser with injection current all conspire to break these conditions. In practice, as the drive current is swept, the laser repeatedly falls out of lock into its noisy free-running state, and engineers must surround the chip with photodetectors and electronic feedback loops to hold it in place, inflating size, power consumption, cost and complexity.

The EPFL team’s insight was to identify a previously unrecognized control parameter that governs how the laser behaves as it tunes from one cavity resonance to the next. They call it feedback-phase dispersion: the difference in the phase of the back-reflected light between consecutive resonances of the microresonator. Because the resonator supports a comb of resonances separated by its free spectral range, and because the phase of the reflected light is periodic, the relative phase from one resonance to the next determines whether the laser, while tuning, always has a good locking state available or instead passes through regions where only poor locking exists. If the locking ranges of adjacent resonances overlap in the right way, the laser is forced to hop directly from one narrow-linewidth state to another, never touching the free-running regime.

Crucially, the researchers found that this dispersion can be engineered geometrically, and at a scale far coarser than the optical wavelength. The phase of light reflected from the resonator depends on the round-trip delays in the bus waveguide that feeds the resonator and the drop waveguide that extracts it, as well as on the position of the drop coupler along the resonator’s spiral path. A simple expression relates the feedback-phase dispersion to these delays and to the resonator’s free spectral range. For a typical 1-gigahertz free spectral range, the relevant length scale is about 30 centimetres, meaning the coupler positions need only be controlled to within centimetres rather than nanometres. That is a manufacturing-friendly tolerance, and it is what makes the approach scalable rather than a laboratory curiosity.

To make the feedback deterministic, the team equipped their spiral silicon nitride resonators with a drop port terminated by an integrated Sagnac loop mirror, which robustly excites the counterpropagating resonator mode and reflects it back to the laser. Without such a mirror, the feedback comes from random Rayleigh backscattering, and its phase fluctuates unpredictably from device to device. With the mirror, the phase evolution becomes stable and, more importantly, predictable from the layout. The researchers fabricated three resonator variants with different port placements and measured their light-current curves. The device without a drop port showed irregular, fluctuating resonance shapes, while the mirror-terminated devices showed stable, reproducible phase evolution that matched the design formula closely, confirming that feedback-phase dispersion is a genuine, engineerable quantity.

The demonstration of endless locking itself is striking. The team butt-coupled an off-the-shelf DFB diode emitting at 1,548 nanometres to a spiral resonator with a free spectral range of 1.44 gigahertz and an intrinsic quality factor of 11.3 million, engineered to have a positive feedback-phase dispersion of 0.16π. When the coupling between the diode and the chip was deliberately weakened, the light-current curve showed the familiar signature of failure: locked plateaus separated by bright intervals in which the laser fell free-running. When the coupling was raised to its design value, the plateaus merged, and the laser transitioned directly from one locked state to the next. Beating the output against a stable reference laser while sweeping the current over more than two full periods of the feedback-phase oscillation revealed a spectrogram in which the laser never once dropped into a free-running state, hopping instead across multiple resonances whenever doing so improved the linewidth.

The contrast case sealed the argument. A second resonator, nearly identical in every parameter except that its port placement produced a negative feedback-phase dispersion of −0.57π, showed exactly the predicted pathology: sections of the current sweep in which the laser unlocked and ran free. Numerical simulations reinforced the picture, showing that positive dispersion values allow the laser to select a high-quality locking state at every possible free-running frequency, whereas values near zero or negative leave gaps in which only weak locking exists. The team defines an endlessly locked laser quantitatively as one whose linewidth reduction factor exceeds 1,000 across the entire drive current range, and their device met that bar comfortably.

The measured performance places the chip among the best integrated lasers ever reported. Sweeping the injection current from 154 to 300 milliamperes in 2-milliampere steps, with no active control of current or phase, the researchers recorded frequency noise reductions of more than 5,000 relative to the free-running diode at every single step. Intrinsic linewidths fell below 10 hertz, a reduction of at least a factor of 10,000, approaching the fundamental thermorefractive noise floor of the silicon nitride resonator itself, the point at which tiny temperature fluctuations in the glass set the ultimate limit. The team also integrated monolithic piezoelectric actuators onto the chip, which strain the resonator to tune its resonances rapidly and with low hysteresis. Driving these actuators with a 10-kilohertz triangular waveform produced mode-hop-free frequency chirps spanning 1.5 gigahertz, exceeding the resonator’s free spectral range, at every injection current, with state-of-the-art linearity.

What elevates the result beyond a record is its generality. The authors show through simulations that the design rule, a relatively low free spectral range combined with a non-zero, preferably positive feedback-phase dispersion, should extend to Fabry–Pérot diodes, to resonators with free spectral ranges beyond 2 gigahertz when the dispersion is near 0.6π, and to photonic platforms operating from the ultraviolet through the mid-infrared. The underlying physics applies equally to bulk crystalline microresonators. With output power of several milliwatts, comparable to state-of-the-art precision lasers, and a footprint set by a single diode chip and a photonic integrated circuit, the architecture converts self-injection locking from a finicky laboratory procedure into a turnkey component. For applications from optical clocks and quantum sensors to coherent LiDAR and fibre sensing, that could mean hertz-level coherence no longer confined to optics tables, but manufactured by the millions on wafers and deployed wherever a quiet, stable beam of light is needed.

Subject of Research: Self-injection-locked silicon nitride photonic integrated lasers with engineered feedback-phase dispersion for robust ultralow-noise operation

Article Title: Endlessly self-injection-locked photonic integrated lasers

Article References: Reichler, M., Bianconi, S., Zhang, Y., Liffredo, M., Villanueva, L. G., & Kippenberg, T. J. (2026). Endlessly self-injection-locked photonic integrated lasers. Nature Photonics, 20(10), 1146-1152. https://doi.org/10.1038/s41566-026-01985-1

Image Credits: AI Generated

DOI: 10.1038/s41566-026-01985-1

Keywords: self-injection locking, photonic integrated circuits, silicon nitride, narrow-linewidth lasers, microresonators, semiconductor lasers, feedback phase, frequency noise, optical atomic clocks, LiDAR, piezoelectric tuning, EPFL

Writing in Light: Science & Applications, Peng and colleagues report a device they describe as a robust single-mode laser based on merging bound states in the continuum, or BICs. Their platform is a photonic-crystal slab laser built on InGaAsP multiple quantum wells. By tuning the diameter of the air holes etched into the slab, the researchers move accidental BICs in momentum space and merge them with a symmetry-protected BIC at the Gamma point, the center of the Brillouin zone. In an ideal, infinite photonic crystal, this merging broadens the high-Q region around Gamma: instead of a narrow, isolated high-Q point, radiative loss remains suppressed over a larger domain of in-plane wave vector. The concept builds on the topological picture of BICs as polarization singularities carrying conserved topological charges, and on the earlier experimental demonstration that merging multiple BICs can create ultrahigh-Q guided resonances that are robust against out-of-plane scattering.

At first glance, one might expect the exact merging point to be the optimum laser design, because it delivers the broadest radiative protection. Peng and colleagues show that this intuition is incomplete, and their correction is the most consequential finding of the study. In a finite photonic crystal, the continuous BIC band of the ideal infinite slab is quantized into discrete, cavity-like modes. The desired fundamental state and the nearby higher-order states are therefore not independent of the BIC landscape; they both sample it. If the high-Q region becomes too broad, it can protect the competing modes just as effectively as the target mode. The result is a lower absolute threshold, but a weaker single-mode hierarchy, because the very mechanism that shields the wanted mode also shields its rivals.

The key message of the paper is that the most robust single-mode laser is obtained not exactly at the merging condition, but slightly before it. In this pre-merging regime, the fundamental s-like BIC-derived mode is already strongly protected, while the nearest p-like competing mode still experiences substantially larger loss. The authors calculate that in the pre-merging device, the threshold gain of the p-like competitor is more than three times larger than that of the s-like lasing mode. At exact merging, this contrast collapses to only about 1.3. Experimentally, the difference is decisive: the pre-merging device remains strictly single-mode up to 80 times threshold, whereas at the merging condition a higher-order BIC-derived mode begins to lase at high pump power. The pre-merging point is, in effect, a sweet spot where protection is strong enough for the target mode but no longer generous enough for its competitors.

This reframes the role of BIC merging in active devices. Merging BICs were originally attractive because they suppress radiative leakage and make high-Q resonances more robust against fabrication disorder and finite angular spread of the pump. Super-BIC lasers have already exploited this principle to reduce threshold by merging symmetry-protected and accidental BICs in momentum space. What Peng and colleagues add is an explicitly active-laser criterion: one should not maximize Q blindly, but should instead maximize the useful threshold contrast between the desired mode and the nearest competing modes. The relevant figure of merit is therefore not simply the quality factor itself, but something closer to the ratio of the modal gains of the target and competing modes, or more generally the separation between the first and second lasing thresholds under realistic gain saturation.

The distinction matters most for miniaturized BIC lasers. Ideal BICs are Bloch modes of extended periodic structures, and their high-Q character is usually compromised when the device is made small. Reducing the lateral size increases edge leakage, broadens the momentum distribution of the confined field, and weakens the infinite-lattice protection that makes BICs attractive in the first place. Early BIC lasing experiments demonstrated that lasing action could persist in finite arrays, even down to a few periods of the crystal. The broader mini-BIC problem, however, is more subtle: how can one retain BIC-like vertical confinement while also providing in-plane confinement in a genuinely small footprint, without sacrificing the very quality factors that motivated the design?

Several research groups have addressed this question by combining BIC physics with additional lateral confinement mechanisms. One team demonstrated miniaturized BIC cavities with ultrahigh quality factors by combining lateral photonic-bandgap confinement with vertical BIC protection, reaching very high Q in small modal volumes. Others then used mini-BIC cavities with quantum-dot gain media to demonstrate low-threshold single-mode nanolasers, and subsequently achieved ultra-low-threshold continuous-wave operation with quantum-dot mini-BIC lasers. A further approach achieved confinement through topological band inversion, producing electrically pumped compact bulk lasers driven by band-inverted bound states in the continuum. These works established that mini-BICs can overcome the apparent incompatibility between BIC physics and small mode volume, but they often rely on a designed cavity region embedded within a larger photonic environment rather than on the patterned region alone.

Peng and colleagues attack the problem from a different angle. In their device, the entire patterned photonic-crystal region spans only five by five periods, an area of roughly 15 square micrometers. At this scale, one cannot simply assume that the structure behaves as a truncated version of an infinite BIC lattice; edge leakage becomes a dominant part of the cavity physics. The authors therefore engineer the boundary holes, reducing their diameter relative to the central holes, to suppress leakage and recover BIC-derived lasing in an extremely small patterned region. The significance is not merely that a small cavity tends to have fewer modes. Reducing the area generally increases mode spacing and can make single-mode operation easier in a trivial spectral sense. The real challenge is different: a very small BIC laser may lose the high-Q advantage that made the BIC useful in the first place. The new work shows that merging-BIC physics, finite-size quantization and edge engineering can be combined so that compactness does not simply destroy BIC protection.

The findings also connect to a parallel development in passive BIC photonics. Recently, the merging of accidental BICs with net-zero topological charge was shown to reshape the polarization texture of the emitted field, stretching the range of circularly polarized emission over a sizeable momentum-space domain. Taken side by side with the new laser result, this suggests that BIC engineering may eventually move beyond selecting a single frequency and spatial mode, toward selecting a single handedness or spin channel. That would open a possible conceptual route toward chiral or spin-selective BIC lasers, in which the same topological machinery that suppresses radiation loss also dictates the polarization state of the output beam.

The broader implication is that BIC lasers are entering a regime where topology, finite-size physics and gain competition must be designed together. Passive BIC photonics asks how radiation can be canceled. Active BIC photonics asks a harder question: after radiation is canceled for one state, which other states are also helped, and will any of them lase? Peng and colleagues answer by identifying a pre-merging sweet spot, demonstrating that the best laser is not located at the point of maximum radiative protection, but at the point where radiative protection is most selective. That principle, established here in a photonic-crystal slab small enough to fit comfortably within a few wavelengths of light, may become a standard design rule for compact, stable and eventually electrically pumped BIC lasers, and a reminder that in laser engineering, as in many fields, the optimum rarely coincides with the maximum.

Subject of Research: Modal selectivity in compact merging-bound-state-in-the-continuum photonic-crystal lasers

Article Title: Single-mode lasers before the merger

Article References: Zito, G. (2026). Single-mode lasers before the merger. Light: Science & Applications, 15(1), Article 372. https://doi.org/10.1038/s41377-026-02467-3

Image Credits: AI Generated

DOI: 10.1038/s41377-026-02467-3

Keywords: bound states in the continuum, photonic crystals, semiconductor lasers, single-mode lasing, quality factor, modal selectivity, InGaAsP quantum wells, miniaturized lasers, topological photonics, threshold discrimination, gain competition, nanophotonics

The vice presidency is a particularly consequential position within Optica’s governance structure. The society operates on a well-defined leadership ladder in which the vice president advances to president-elect and then to president, meaning that the person elected to the 2027 vice presidency is effectively being positioned to guide the organization’s strategic direction in the years that follow. Optica’s board is responsible for overseeing a portfolio that includes flagship scientific meetings, a family of peer-reviewed journals, industry partnerships, education and outreach programs, and policy engagement on behalf of researchers working across optics and photonics. With more than 400,000 members and constituents across the globe, the society’s decisions about which conferences to grow, which emerging subfields to champion, and how to support early-career scientists ripple widely through the community. The election of a new vice president therefore attracts close attention from researchers who want to see their priorities reflected at the top of the organization.

Delfyett’s election brings to the board one of the most technically accomplished figures in ultrafast optics and semiconductor laser research. His scientific reputation was established in part during his time at Bellcore, where he developed what has been described as the world’s fastest and most powerful mode-locked semiconductor laser diode. Mode-locked lasers are devices that produce trains of extremely short optical pulses, often lasting femtoseconds or picoseconds, by locking the phases of many longitudinal modes within the laser cavity. Achieving that feat in a semiconductor diode format, rather than in bulky solid-state systems, opened pathways toward compact, high-repetition-rate sources suitable for telecommunications, clocking, signal processing, and precision measurement. That line of research remains central to modern photonics, as mode-locked semiconductor lasers underpin technologies ranging from optical frequency combs to high-speed data transmission in fiber networks.

Since 1993, Delfyett has built his research program at CREOL, the University of Central Florida’s internationally regarded optics and photonics school, where he directs the Townes Laser Institute and holds the rank of University Distinguished Professor. His scholarly output is extensive: he has authored more than 850 publications and holds 45 U.S. patents, and he has translated laboratory advances into the commercial sphere as a co-founder of Raydiance, Inc., a company associated with ultrafast laser technology. His contributions have been recognized with election to the National Academy of Engineering, the American Physical Society’s Arthur L. Schawlow Prize, and the 2026 SPIE Harold E. Edgerton Award, an honor named for the pioneering electrical engineer and photographer whose stroboscopic imaging work became iconic. He is also a Fellow of APS, AAAS, Optica, the IEEE Photonics Society, SPIE, the National Society of Black Physicists, and the National Academy of Inventors, a collection of distinctions that reflects both scientific depth and breadth of service.

Beyond the laboratory, Delfyett has accumulated a long record of volunteer leadership within the scientific publishing and conference ecosystem. He has served as Editor-in-Chief of the IEEE Journal of Selected Topics in Quantum Electronics and as Chair of the CLEO Steering Committee, the body that helps guide one of the field’s largest annual conferences on lasers and electro-optics. His prior governance experience includes service on Optica’s own Board of Directors, membership on the Board of Governors of the IEEE Photonics Society, the chairmanship of the APS Division of Laser Science, and the presidency of the National Society of Black Physicists. That combination of editorial, conference, and society leadership is precisely the kind of institutional fluency that Optica’s membership tends to reward in board elections, and it positions him to step into the society’s presidential succession track with an intimate knowledge of how its programs operate.

Optica CEO Elizabeth Nolan welcomed the election, emphasizing both Delfyett’s scientific legacy and his service record. According to the society’s announcement, Nolan described him as someone who has spent his career pushing the boundaries of what ultrafast lasers can do, whose vision has helped shape modern photonics, and who is a strong leader, a brilliant scientist, and a dedicated volunteer. She added that the society is thrilled to welcome him to the Board of Directors, where his experience and expertise will help Optica meet the evolving needs of the optics and photonics community. The remarks signal that the board expects Delfyett’s perspective as both a researcher and an entrepreneur to inform its decisions at a time when photonics is expanding into new commercial territory, from silicon photonics in data centers to laser-based manufacturing and quantum technologies.

The two Directors at Large positions, covering the 2027 through 2029 term, went to figures who represent complementary corners of the discipline. Sterling Backus is an Advanced Project Scientist at Thorlabs, Inc., one of the world’s largest suppliers of photonics hardware and instrumentation, and an affiliate researcher at Colorado State University. His dual footing in industry and academia mirrors the reality of a field in which much of the instrumentation driving discovery is developed and manufactured by companies rather than built entirely in university shops. Within Optica, Backus has served on the Meetings Council, the body that shapes the society’s conference portfolio, and he is the program co-chair for the society’s Frontiers in Optics meeting for 2026 and 2027. He is an Optica Fellow and previously served as CLEO program chair in 2017 and general chair in 2019, experience that gives him detailed insight into how large-scale scientific meetings are planned, funded, and adapted to changing community needs.

Frédérique Vanholsbeeck brings a distinctly international and interdisciplinary dimension to the board. She is a professor of physics at Waipapa Taumata Rau, the University of Auckland in New Zealand, where she leads one of Aotearoa New Zealand’s most active biophotonics groups. Biophotonics, the application of light-based technologies to biology and medicine, is among the fastest-growing areas of the field, encompassing optical coherence tomography, fluorescence microscopy, laser tweezers, and optical diagnostics for clinical use. Research groups in this area often sit at the interface of physics, engineering, and the life sciences, and leaders like Vanholsbeeck help ensure that the society’s programs serve researchers who do not fit neatly into traditional disciplinary boxes. Her governance experience includes the presidency of the Australian and New Zealand Optical Society, membership on a Marsden Fund panel, which distributes New Zealand’s major fundamental research grants, and multiple leadership roles in major international and regional conferences. She is also an Optica Fellow.

The geographic and sectoral balance of the new slate is notable. Optica has long emphasized its role as a global society, and the election of a director based in New Zealand alongside two United States-based leaders, one from a university research center and one from industry, reflects an attempt to keep the board representative of a membership that spans continents and career contexts. For researchers in Oceania and the broader Asia-Pacific region, Vanholsbeeck’s presence at the governance table offers a direct channel for the concerns of smaller national optical societies, which often face challenges distinct from those of large North American and European institutions, including limited access to major facilities and the logistical burden of distance from the field’s dominant conference hubs.

For the wider photonics community, the elections arrive at a moment when the discipline’s profile has never been higher. Optical technologies now carry the world’s internet traffic, guide autonomous vehicles, enable the precision manufacturing of semiconductors, and provide the measurement backbone for breakthroughs in timekeeping, navigation, and fundamental physics, including the laser interferometry behind gravitational-wave detection. The leaders chosen to steer Optica’s board will influence how the society invests in meetings, publications, and advocacy as these applications multiply. With Delfyett’s ultrafast laser expertise, Backus’s industry-grounded perspective on instrumentation and conferences, and Vanholsbeeck’s biophotonics and international leadership, the incoming directors bring a blend of technical depth and organizational experience that mirrors the field itself: fast-moving, commercially vital, and increasingly global.

Subject of Research: Election of new leaders to the board of the Optica optics and photonics society

Article Title: Peter J. Delfyett, Sterling Backus and Frédérique Vanholsbeeck will serve on Optica’s Board of Directors

Article References: Peter J. Delfyett, Sterling Backus and Frédérique Vanholsbeeck will serve on Optica’s Board of Directors. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Optica, Peter J. Delfyett, Sterling Backus, Frédérique Vanholsbeeck, ultrafast optics, semiconductor lasers, biophotonics, photonics, board of directors, CREOL, Thorlabs, University of Auckland

Space-time wave packets are a distinctive class of optical fields in which the spatial and temporal degrees of freedom of light are deliberately coupled. In an ordinary laser beam, spatial diffraction and temporal dispersion behave independently: the beam spreads as it travels, and the pulse stretches as it propagates through dispersive media. Wave packets break this rule by enforcing a rigid spectral-spatial correlation — each frequency component of the light is assigned a specific transverse spatial scale. When engineered correctly, this coupling produces propagation-invariant light sheets whose transverse profile remains essentially unchanged over long distances, regardless of how broad the underlying spectrum may be.

Until now, synthesizing such fields required routing laser light through pairs of diffraction gratings placed in Fourier-conjugate planes, with a spatial light modulator sandwiched between them to imprint the necessary correlations. The new device collapses that entire signal-processing chain into the gain medium itself. The team fabricated arrays of distributed feedback lasers with a dual-ended geometry, meaning each laser cavity emits coherent sub-beams from both ends simultaneously. These mutually coherent outputs carry stable phase contrasts between one another, providing exactly the controlled superposition needed to sculpt the spectral-spatial structure of the emitted field.

The physics of the device builds on the coupled-wave theory of distributed feedback lasers, a technology that dates back to the seminal work of Kogelnik and Shank in 1972. By lithographically defining a periodic grating along the gain region, engineers can force a semiconductor laser to oscillate on a single longitudinal mode with exceptional spectral purity. The innovation here lies in arranging multiple such emitters in an array and orchestrating their mutual coherence so that the collective emission acquires a designed spectral tilt — a linear relationship between emission frequency and transverse wave vector that is the hallmark of a space-time wave packet.

The versatility of the architecture proved remarkable in experiments. By tuning the spectral tilt angle of the array, the researchers could command the emitted beams to exhibit dramatically different propagation behaviors, sweeping through a family of space-time light sheets with controllable group velocities. The width of the generated wave packets proved scalable, as did the propagation length over which invariance is maintained. Crucially, the platform supports both incoherent and coherent synthesis regimes: in the incoherent mode, statistically independent spectral components combine to form non-diffracting broadband fields, a capability that had previously demanded elaborate external processing.

Among the most striking demonstrations was self-healing. When the researchers obstructed part of the beam’s path, the wave packet reconstituted its transverse profile after the obstruction, inheriting the resilience that Bessel beams and other diffraction-free fields are famous for. This behavior arises because each spatial region of the beam draws energy from an extended reservoir of spectral components; removing a portion of the field leaves the remaining components free to interfere and refill the shadow. The team also mapped the full spatiotemporal structure of the emitted light and demonstrated precise phase control across the array, confirming that the device delivers on every theoretical promise made for integrated structured-light sources.

The implications ripple across multiple domains. In microscopy and tomography, propagation-invariant light sheets promise sharper, deeper imaging with less degradation through scattering media, an area where space-time light-sheet microscopy is already showing early promise. In optical communications, structured light — including orbital angular momentum modes that have enabled terabit-scale free-space data transmission — offers new multiplexing dimensions, and a chip-based source makes such schemes compatible with the footprint and cost constraints of real networks. In ultrafast science, where attosecond pulse shaping has historically demanded table-sized pulse shapers, compact sources with built-in spatiotemporal control could democratize access to advanced light-matter experiments.

The work also represents a conceptual milestone for laser engineering itself. The field of integrated laser arrays has matured through supersymmetric designs, topological modes stabilized via exceptional points, and parity-time-symmetric microring lasers — each exploiting novel physics to control how emitters combine. This new platform extends that trajectory by uniting field structuring and lasing within a single device: the laser is no longer merely a source of light to be shaped afterward, but the shaper itself. That inversion could fundamentally change how photonic engineers think about on-chip beam combining and spatiotemporal signal processing.

Challenges remain before such arrays reach commercial deployment, including scaling output power, extending operation across wavelength bands, and refining thermal management. Yet the demonstration stands as a compelling proof of principle. The theoretical scaffolding — from diffraction-free beams first reported in 1987 to the modern framework of space-time wave packets elaborated over the past decade — has now met a practical, lithographically defined emitter. What once required an optical table the size of a room now fits within a semiconductor die, and the bridge between structured-light physics and integrated photonics that researchers have sought for years has finally been built.

As the technology matures, one can imagine photonic chips that emit perfectly tailored, diffraction-free, self-healing beams at the push of a current, ready to thread through scattering tissue, carry multiplexed data through turbulent air, or drive next-generation ultrafast systems. The study, supported by the Office of Naval Research, the Department of Energy, the Army Research Office, the Air Force Office of Scientific Research, the W. M. Keck Foundation and the Simons Foundation, signals that the era of on-chip space-time optics has moved from theoretical aspiration to engineering reality.

Subject of Research: On-chip generation of space-time wave packets using an integrated distributed feedback semiconductor laser array

Article Title: On-chip space–time wave packet laser array

Article References: Lee, J., Ren, H., Liu, Y. G. N., Yessenov, M., Wei, Y., Huh, B., Vasdekis, A. E., Christodoulides, D. N., Abouraddy, A. F., & Khajavikhan, M. (2026). On-chip space–time wave packet laser array. Nature Photonics. https://doi.org/10.1038/s41566-026-02003-0

Image Credits: AI Generated

DOI: 10.1038/s41566-026-02003-0

Keywords: space-time wave packets, integrated photonics, semiconductor lasers, distributed feedback lasers, structured light, diffraction-free beams, self-healing beams, spatiotemporal optics, laser arrays, beam shaping, optical communications, Nature Photonics