We demonstrate the first electrically pumped quantum-dot (QD) lasers grown on recessed 300 mm Si wafers, with maximum CW lasing output power of 125 mW at 20 °C. This significant advance in heteroepitaxial integration of III-V gain elements onto existing CMOS-compatible Si photonic circuits is promising for photonic integrated circuit integration.
We demonstrate an electrically synchronized two-color all-semiconductor mode-locked laser system operating at a repetition rate of 282 MHz, generating picosecond pulses centered at 974 nm and 833 nm with peak powers exceeding 100 W and 80 W respectively and a $\text{TEM}_{00}$ mode profile at output.
We design a quantum-dot single-photon source with a defect-based photonic crystal cavity on a SiN waveguide that subdues crosstalk from resonant excitation and has >90% coupling efficiency. It is expected to efficiently generate single photons with high purity and indistinguishability for scalable integrated quantum photonics.
We demonstrate a GaSb/Si3N4 Vernier hybrid laser with a wide tuning range of 170 nm around $2.55\ \mu \mathrm{m}$, exhibiting > 1 mW of output power in continuous wave over the entire band, making such laser very attractive for sensing applications.
We successfully improved characteristics of ridge structured QD-LD and demonstrated threshold current of 9.5 mA and corresponding threshold current density of 0.34 kA/cm2, whose value was the lowest class previously reported as $1.55 \mu\mathrm{m}$-band edge emitted type QD-LDs to the best of our knowledge.
An InP based QD laser with InAs quantum dots (QDs) emitting at $1.3\ \mu\mathrm{m}$ wavelength was realized. A high modal gain of 15 cm−1 per QD layer, low internal absorption value of 11 cm−1 and high internal quantum efficiency of 82% were obtained.
An InP based QD laser with InAs quantum dots (QDs) emitting at $1.3\ \mu\mathrm{m}$ wavelength was realized. A high modal gain of 15 cm−1 per QD layer, low internal absorption value of 11 cm−1 and high internal quantum efficiency of 82% were obtained.
The semiconductor laser is among the most important inventions of the 20th century, having paved the way for our information society. More than sixty years after its demonstration, the laser remains a crucial enabling device for many emerging photonics applications. Present-day commercial semiconductor lasers, including edge-emitting lasers and VCSELs, use cavity mode volumes that are many times larger than the characteristic volume $V_{\lambda}= (\lambda/(2n))^{3}$ , defined by a cube half-wave of wavelength $\lambda$ in a material with refractive index $n$ . The theory of such macroscopic lasers is now well understood [1]. For future on-chip optical interconnects, e.g. between the cores of a computer, it is, however, essential to develop microscopic lasers with ultra-small footprints and ultra-low energy consumption. The emergence of point-defect cavities in photonic bandgap structures and nanofabrication technology developments have facilitated such a new generation of nanolasers with ultra-small mode volumes [2]–[5]. By virtue of enhanced light-matter coupling due to Purcell effects in nanocavities and a significant rate of spontaneous emission into the lasing mode, these nanolasers challenge existing laser theory. In particular, questions are raised about the correct description of the gain of the lasers, as well as the minimum level of quantum noise and the maximum modulation speed attainable.
We present a broadband planarized THz quantum cascade laser with inverse-designed waveguide facets, coupled to a broadband patch array antenna for surface emission. We measure an emission spectrum spanning 800 GHz, a peak power of 13.5 mW and a symmetric far-field pattern with a narrow beam divergence of $(21^{\circ}\ \mathrm{x}\ 20^{\circ})$ .
O-band quantum dot lasers with co-doping reduce threshold current density relative to the undoped case, for 1mm long uncoated lasers from 245Acm−2 to 132Acm−2 at 27°C and 731Acm−2 to 312Acm−2 at 97°C. Improvements are also significant compared to lasers employing any one doping strategy.
InP-based quantum cascade lasers on (001) GaAs with watt-level output power and low pulsed threshold-current density at RT. A 35-stage $\ln 0.53\text{GaAs}/\text{In}0.52\text{AlAs}$ lattice-matched active-region QCL is grown by MOCVD, on an InP metamorphic buffer with strained InAs or InGaAs quantum wells as dislocation filters.
Although the fiber optic backbone had been completed, R&D of semiconductor lasers became more active with the goal of longer and faster transmissions. The $1.55 \upmu\mathrm{m}$ band had contributed significantly to longer distances, but required a new challenge, the development of single-mode laser under high-speed modulations. The DFB enabled single mode lasing, however modulation-induced chirping was still a problem for higher speed. Modulation schemes were analyzed theoretically and experimentally to reduce the chirping. This study enabled high-speed transmission up to 10 Gb/s, but also revealed a fundamental trade-off between chirping linewidth and modulation speed. This trade-off, would limit transmission length and bitrate, promoted developments of new devices, including the external feedback laser, the multi-electrode DFB laser, and the EA integrated DFB laser.
Waveguide loss spectrum in an InGaN laser diode (LD) has been measured and the results were compared with an InGaP LD. It is observed that the spectrum has a long tail in the InGaN LD while it shows a sharp rise in the InGaP LD.
In this work, we demonstrate control over the time-domain state quantum cascade laser output state using microwave modulation. We demonstrate narrow, pulse-like features with a full-with at half-maximum of 558 fs when isolated, which corresponds to the expected Fourier-transform limited pulse-width.
We demonstrate solid-state VCSEL beam scanners integrated with multi-grating pitch tunable seed VCSELs for expanding FOV and scanning resolutions. The total FOV of over $12^{\circ}$ and the corresponding resolution points of 166, which could be double in comparison with a single VCSEL beam scanner.
We report theoretically and experimentally open-Dirac cavities that exploit symmetry-dependent scaling of losses in cavities with a linear dispersion. We experimentally demonstrate that single-mode lasing from surface emitting lasers operating around the open-Dirac singularity is maintained even when the cavity is scaled up to arbitrary sizes. Our work constitutes the first scale-invariant surface emitting laser.
