GaInAsN/GaAs quantum dot laser diodes operating in 1.36 /spl mu/m wavelength range

For the first time, a pseudomorphic GaInAsN DWELL laser with laser emission at 1.36 /spl mu/m and a low transparency current density (206 A/cm/sup 2/) grown by molecular beam epitaxy is reported. The GaInAsN DWELL laser shows a redshift in comparison to an N-free GaInAs DWELL laser of about 90 nm and a transparency current density of 35 A/cm/sup 2/ per single QD layer.     

1.42 /spl mu/m continuous-wave operation of GaInNAs laser diodes

Continuous-wave (CW) operation of GaInNAs laser diodes in the 1.4 /spl mu/m range has been realised for the first time. A GaInNAs double quantum well separate confinement heterostructure was grown by solid source molecular beam epitaxy. Threshold currents as low as 66 mA and external efficiencies as high as 0.29 W/A could be demonstrated in CW operation. Lasing was observed up to 150/spl deg/C and a characteristic temperature T/sub 0/ of 111K was demonstrated. The emission wavelength at room temperature was centred at 1417 nm.     

GaInNAs-based distributed feedback laser diodes emitting at 1.5 /spl mu/m

For the first time, GaAs-based 1.5 /spl mu/m singlemode emission has been realised utilising GaInNAs active-layer material and lateral distributed feedback. The double quantum well separate confinement laser structure was grown by plasma-assisted molecular beam epitaxy. A threshold current of 240 mA and an external efficiency of 0.11 W/A could be demonstrated with a sidemode suppression ratio of better than 26 dB in pulsed operation. Singlemode emission up to 1506.5 nm has been realised.     

Very-low-threshold 2.4-/spl mu/m GaInAsSb-AlGaAsSb laser diodes operating at room temperature in the continuous-wave regime

A GaInAsSb-AlGaAsSb large optical cavity triple-quantum-well structure was grown by molecular-beam epitaxy. Shallow mesa ridge-waveguide lasers with stripe width of 100 /spl mu/m were fabricated and tested. An internal losses coefficient as low as 4 cm/sup -1/ and a high internal quantum efficiency of 70% were obtained. In the pulsed regime at room temperature, the extrapolated threshold current densities for infinite cavity length is 78 A/cm/sup 2/. The threshold current density per quantum well is as low as 34 A/cm/sup 2/ for a 3-mm-long cavity.     

1.53 /spl mu/m GaInNAsSb laser diodes grown on GaAs(100)

GaInNAsSb/GaNAs double quantum well ridge waveguide laser diodes with room temperature lasing wavelength of 1532 nm are reported. The devices exhibit leakage-corrected threshold current densities as low as 969 A cm/sup -2/ per quantum well in pulsed mode, with characteristic temperatures as high as 90 K.     

Tunable self-seeded semiconductor disk laser operating at 2/spl mu/m

A 2 mum semiconductor disk laser with a tuning range of 35 nm and output power exceeding 500 mW is reported. The method for generating wavelength-tunable radiation is based on self-seeding the disk laser using optical feedback from a diffraction grating     

9.7 GHz small-signal bandwidth of three-quantum well GaInNAs/GaAs laser diodes operating at 1.35 /spl mu/m

High frequency characterisation of three-quantum well GaInNAs/GaAs lasers operating at 1.35 /spl mu/m is reported. A relaxation frequency as high as 7.4 GHz and a 9.7 GHz small-signal bandwidth are demonstrated, indicating the potential for high bit rate (10 Gbit/s) direct modulation of these dilute nitrides on GaAs devices.     

Photonic-crystal surface-emitting laser near 1.55 /spl mu/m on gold-coated silicon wafer

An InP/InGaAs-based photonic band-edge laser bonded on silicon operating near 1.55 mum is presented. A gold reflector positioned below the slab containing the active layer reduces the optical losses of the Bloch-mode resonator. As a result, a quality factor exceeding 8000 is obtained at transparency leading to a laser threshold as low as 3.4 muJ/cm²     

2.3 /spl mu/m type-I quantum well GaInAsSb/AlGaAsSb/GaSb laser diodes with quasi-CW output power of 1.4W

Improvement of the output parameters of 2.3 mum GaSb-based laser diodes was observed with increase of the quantum-well compressive strain. A continuous-wave (CW) power of 1.15 W and quasi-CW power of 1.4 W were obtained at room temperature from 2 mm-long single emitters with a 100 mum-aperture.     

Room-temperature continuous-wave operation of GaInNAsSb laser diodes at 1.55 /spl mu/m

The first 1.55 /spl mu/m room-temperature continuous-wave (CW) operation of GaAs-based laser diodes utilising GaInNAsSb/GaNAs double quantum well active regions grown by molecular beam epitaxy is reported. In electrically-pumped CW operation the narrow ridge waveguide devices have a room temperature lasing wavelength of 1550 nm near threshold, increasing to 1553 nm at thermal rollover. The CW threshold current was 132 mA for a 3/spl times/589 /spl mu/m device, with a characteristic temperature of 83 K, measured in pulsed mode between 20 and 70/spl deg/C.     

Room-temperature InAs=AlSb quantum-cascade laser operating at 8.9 /spl mu/m

A room-temperature InAs/AlSb quantum-cascade laser operating at 8.9 mum is reported. The laser structure is grown on an n-InAs (100) substrate by solid-source molecular-beam epitaxy. The active region utilises a diagonal intersubband transition in an InAs/AlSb three-quantum-well structure. Observed threshold current density in pulse mode is 2.6 kA/cm² at 80 K and 12.0 kA/cm² at 300 K. The maximum operation temperature is 305 K     

Interband cascade laser operating to 269 K at /spl lambda/=4.05 /spl mu/m

A ten-stage interband cascade laser with 13 mum-wide, 4 mm-long ridge waveguide and Au electroplating for improved epitaxial-side-up heatsinking operates CW to a temperature of 269 K, where the emission wavelength is 4.05 mum. Maximum CW output powers are 130 mW at 78 K, 58 mW at 200 K, and 9 mW at 260 K, and the threshold current density at T=260 K is 660 A/cm²     

Continuous-wave operation of quantum cascade laser emitting near 5.6 /spl mu/m

Buried heterostructure quantum cascade lasers emitting at 5.64 /spl mu/m are presented. Continuous-wave (CW) operation has been achieved at -30/spl deg/C for junction down mounted devices with both facets coated. A 750 /spl mu/m-long laser exhibited 3 mW of CW power with a threshold current density of 5.4 kA/cm/sup 2/.     

Resonant-phonon terahertz quantum-cascade laser operating at 2.1 THz (/spl lambda//spl sime/141 /spl mu/m)

The development of quantum-cascade lasers (QCLs) at 2.1 THz (/spl lambda//spl sime/141 /spl mu/m), which is the longest wavelength QCL to date without the assistance of magnetic fields, is reported. This laser uses a structure based on resonant-phonon depopulation, and a metal-metal waveguide to obtain high modal confinement with low waveguide losses. Lasing was observed up to a heatsink temperature of 72 K in pulsed mode and 40 K in continuous-wave (CW) mode, and 1.2 mW of power was obtained in CW mode at 17 K.     

Strongly sub-Poissonian electrical noise in 1.55-/spl mu/m DBR tunable laser diodes

We report terminal electrical noise measurements on 1.55-/spl mu/m DBR tunable laser diodes in the 1 Hz-1 MHz frequency range, performed using an electrical correlation method. These measurements are compared with a comprehensive electrical model based on rate equation formalism. Taking into account diffusion phenomenon and structural parameters, we obtain a complete agreement between the model and the measurements above threshold and a quite similar tendency below threshold. The influence of Bragg section bias is also discussed.     

High-power highly reliable 1.02-1.06-/spl mu/m InGaAs strained-quantum-well laser diodes

By growing the InGaAs active layer at temperatures lower than in conventional growth, we extended the lasing wavelength and presented the high reliability in InGaAs strained-quantum-well laser diodes. Equivalent I-L characteristics were obtained for 1.02-, 1.05-, and 1.06-/spl mu/m laser diodes with a cavity length of 1200 /spl mu/m. Maximum output power as high as 800 mW and fundamental transverse mode operation at up to 400 mW were obtained at 1.06 /spl mu/m and an 1800-/spl mu/m cavity. Stable operation was observed for over 14 000 h under auto-power-control of 225 mW at 50/spl deg/C for the 1.02-, 1.05-, and 1.06-/spl mu/m lasers with a 900-/spl mu/m cavity.     

High-power angled broad-area 1.3-/spl mu/m laser diodes with good beam quality

A new type of high-power laser diodes is fabricated with a broad-area waveguide tilted at 7/spl deg/ from the facet normal. For the current between 0.6 and 1.2 A, it behaves like a superluminescent diode with 40-nm spectral width and 40-mW output power. The far field emits at about 25/spl deg/ away from the facet normal. For the current above 1.2 A, it oscillates with a narrow spectrum. The far field emits along the facet normal with its angle only twice of the diffraction limit. The output power per facet could be 1 W at 12 A.     

1.50 /spl mu/m CW operation of GaInNAs/GaAs laser diodes grown by MOCVD

Room-temperature continuous-wave operation of a 1.5 /spl mu/m range GaInNAs laser grown by metal organic chemical vapour deposition is reported. The lasing wavelength of the GaInNAs/GaAs double quantum well laser was 1.50 /spl mu/m and the threshold current was 245 mA. The characteristic temperature between 10 and 50/spl deg/C was about 119 K under pulse operation.     

Quantum dot superluminescent diodes emitting at 1.3 /spl mu/m

We report ridge-waveguide superluminescent diodes based on five stacks of self-assembled InAs-GaAs quantum dots. Devices with output powers up to 10 mW emitting around 1.3 /spl mu/m are demonstrated. Spectral analysis shows a broad emission peak (26-nm full-width at half-maximum) from the dot ground state at low injection, and an additional peak from the excited state at higher bias. Temperature characteristics in the range 10/spl deg/C-80/spl deg/C are also reported. The experimental curves are in good agreement with simulations performed using a traveling-wave rate equation model.     

GaAs-based four-channel photonic crystal quantum dot laser module operating at 1.3 /spl mu/m

A GaAs-based laser module, which combines the output of four singlemode lasers operating at 1.3 /spl mu/m by using photonic crystal mirrors and combiners, has been developed. The complete device size is around 0.2 mm/sup 2/. The lasers can be operated individually or in parallel with sidemode suppression ratios better than 20 dB.