GaAs/AlGaAs vertical-cavity top-surface-emitting lasers (VCSELs) with a continuously graded mirror composition have been grown by MOCVD, and planar devices proton-implant current confinement characterized. Continuous grading of the heterointerfaces in Bragg reflectors eliminated energy-band discontinuities, thus improving carrier transport resulting substantial reduction series resistance threshold voltage laser diodes. These VCSELs excellent room-temperature CW electrical characteristics,...

InGaAs/AlGaAs laser diode arrays fabricated with differing amounts of In in the quantum well active layer are characterized by threshold currents 115 A/cm2, transparency 50 optical losses 3 cm−1, and wavelengths to 960 nm for compositions 20%. Gain coefficient measurements indicate an increase from 0.0535 0.0691 cm μm/A lasers 0% InAs 10–20% InAs, respectively. The maximum output power achieved a device 100 μm aperture is W cw.

Widely tunable low-threshold current laser diodes fabricated from an engineered multiple-quantum-well (MQW) gain structure consisting of three compressively strained In/sub 0.2/Ga/sub 0.8/As wells different thicknesses are reported. Using a grating in external cavity, continuous-wave tuning range 70 nm (911-981 nm) is measured for 155-μm semiconductor cavity length device at 32 mA. This the lowest reported bias with this broad range. A maximum continuous wave 80 (901-981 has been 95 At long...

Bound states in the continuum (BIC) with high quality factor (Q-factor) and narrow bandwidth can manipulate electromagnetic waves enhance light-matter interactions. This phenomenon has garnered significant attention field of photonics, particularly context all-dielectric metamaterials metasurfaces. Recently, introduction BIC into chiral structures shown that upon circularly polarized light irradiation metasurfaces asymmetry, leaks quasi-BIC (Q-BIC) induces near-unity circular dichroism (CD)....

Chiral BIC can reach ultrahigh quality factors (Q-factor) based on its asymmetry, with broken mirror symmetries and in-plane inversion. Only by structural perturbation chiral quasi-BIC (q-BIC) appear, so it is much more realizable reasonable for the manufacturers in practical productions fabrications considering technology means that are available. In this paper, we design a new dielectric metasurface employing H-shaped silica meta-atoms lattice, which symmetrical structure, obtaining...

A monolithic smart pixel technology based on the integration of two-dimensional arrays cascadable optical switches, logic gates, and switching nodes consisting vertical-cavity surface-emitting lasers heterojunction phototransistors or photothyristors is described. Different combinations these components perform switching, logic, routing, memory, regeneration. Latching, nonlatching, bistable switches with high gain contrast are demonstrated, along all simple single-stage Boolean functions....

The authors report the first demonstration of a cascadable, photonic switch based on monolithic integration multi-quantum-well vertical-cavity surface-emitting laser (VCSEL) and latching pn-pn photothyristor grown by low-pressure metalorganic vapor-phase epitaxy (LP-MOCVD). VCSEL structures can be independently optimized for optical switching, logic, memory functions. Optical switching with high gain (30000), contrast (30 dB), low power (11 nW), have been demonstrated. integrated pn-pn/VCSEL...

Monolithic, multiple-wavelength vertical-cavity surface-emitting laser (VCSEL) arrays have been obtained by the surface-controlled enhancement and reduction of MOCVD epitaxial growth rate, achieving a periodic, graded wavelength span greater than 30 nm. Room-temperature (RT), electrically pumped continuous-wave (CW) lasing is demonstrated, with uniform threshold currents 5.5/spl plusmn/0.5 mA typical output powers 0.5 mW. We show here for first time both rate entire VCSEL structure...

The geometry of quantum well surface-emitting lasers has several important consequences. ultrashort (∼1 μm) vertical cavity defines longitudinal modes with energy separation greater than the bandwidth spectral gain. optical confinement these can approach unity. To achieve lasing, high carrier densities (∼1012 cm−2) in are required. confined carriers interact through enhanced many-body exchange which influences both lasing wavelength and threshold characteristics. Indeed, interaction...

Abstract All-dielectric metasurface with ultra-high quality resonances underpinned by bound states in the continuum (BICs) have attracted lots of attention recent years for they enable new methods wavefront control and light focusing. We study a composed one transverse nanohole (TNs) two identical vertical nanoholes (VNs) lattice, which supports both symmetry-protected accidental BICs (at-Γ off-Γ BICs). Based on destructive interference between surface from TN element VNs element, at-Γ...

In the fields of optics and photonics, topic light-matter interactions, particularly strong coupling effects, is a developing area research. Exciton polariton, hybridized state brought about by coupling, hot topic, especially from standpoint chiral optics. Under incidence right circularly polarized light left (RCP LCP) light, we investigate between excitons quasibound states in continuum (Q-BICs) resonance bulk WS 2 metasurface. It discovered that Q-BICs are affected obviously on center...

Non-radiative bound states in the continuum (BICs) allow construction of resonances with high-quality (Q) factors and have emerged as an attractive platform for manipulating light–matter interactions on nanoscale. However, current studies symmetry-protected BICs (SP-BICs) suffer from a fundamental trade-off between Q factor asymmetric parameters, presenting significant hurdle practical applications. Here, utilizing eigenfield perturbations, we successfully break conventional inverse...

We demonstrate for the first time CW performance of AlGaAs-GaAs vertical-cavity surface-emitting lasers (VCSELs) at cryogenic temperatures from 6 K to 200 K. By detuning cavity mode with respect gain peak so that optimum dc lasing operation is achieved -100 K, we find this can be maintained down as low Across a broad range minimum threshold current 16-μm diameter VCSEL stayed below 4 mA, while its -3-dB modulation bandwidth increased by about 70% 11 GHz and external slope efficiency greater than 70%.

A simple fabrication process for InGaAs strained quantum well leaky-mode laser arrays is demonstrated. The are ten-element devices grown by two-step metal-organic chemical vapor deposition. structure consists of a graded index-separate confinement active region and thin (0.12 mu m), transparent GaAs waveguide region. near-field pattern typical phase-locked was measured. Fundamental mode oscillation observed up to 2 (threshold as low 175 mA). authors 1 s pulsed optical output power 172 mW per...

Cryogenic optical data links require an efficient source with temperature-insensitive continuous-wave (CW) operation at low temperatures. Also, to simplify alignment, it is desirable obtain CW over a broad temperature range that spans both the and high By use of vertical-cavity surface-emitting lasers (VCSELs) chirped (nonuniform) multiple quantum wells (MQWs) broaden gain spectrum, has been achieved from 5-350 K, improved characteristics in high- low-temperature regimes. In particular,...

The first all-semiconductor GaAs/AlGaAs vertical cavity laser incorporating wavelength resonant periodic gain layers grown by metalorganic chemical vapour deposition is reported. optically pumped structure exhibits a threshold of 0.5 nJ at 852 nm for 720 pulsed excitation and energy conversion efficiencies up to ̃6%. output linewidth ≤0.4 FWHM with single longitudinal mode oscillation. An 0.43 (~60 mW) demonstrated 300 K.

Inverting optical logic gates based on the monolithic integration of a vertical-cavity surface-emitting laser (VCSEL) with heterojunction photothyristor (PNPN) are described. Logic functions INVERT, NAND, and NOR experimentally demonstrated for first time using latchable cascadable PNPN/VCSEL switches, which can be triggered very low energy, while producing high gain contrast. These integrable single epitaxial structure to provide multifunctional memory arrays.< <ETX...

A GaAs/AlGaAs vertical-cavity surface-emitting laser with resonant periodic gain has been grown by metal-organic chemical vapour deposition. The as-grown structure exhibits an optically pumped CW threshold below 15 mW at 300 K and a single-ended power efficiency up to 45%. Fundamental Gaussian higher-order modes are observed spectral widths (FWH M) as low 0.27 Å.