Low Threshold CW Operation Research Articles

Low threshold CW operation ofGaInP/AlGaInP DFB lasers at 680 nm

Continuous wave operation of GaInP/AlGaInP DFB lasers at room temperature is reported. The DFB lasers in ridge waveguide geometry show stable singlemode emission with a sidemode suppression > 30 dB and a threshold current of 25.9 mA at 20°C. Singlemode operation could be achieved for a large temperature range between –10 and 40°C. Even for 40°C the threshold current remains below 50 mA.

Circular-grating surface-emitting distributed Bragg reflector lasers on an InGaAs-GaAs structure for 0.48-μm applications

In this paper, we report on the design and fabrication of electrically-pumped circular-grating surface-emitting DBR lasers for operation in the 0.98-/spl mu/m wavelength range. The layer structure with InGaAs-GaAs-AlGaAs strained multiquantum-wells was obtained by one-step epitaxial growth. Circular gratings are defined by electron-beam lithography around circular gain sections of different diameters. Low threshold CW operation as low as 26 mA for a 60-/spl mu/m diameter gain section, and high-power pulsed operation of over 120 mW for a 100-/spl mu/m diameter gain region are demonstrated. A quasi-circular far-field pattern with a divergence of about 1/spl deg/ is obtained.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Low threshold CW operation of circular-grating surface-emitting DBR lasers using MQW and a self-aligned process

In this letter, we present the first room temperature continuous wave operation of circular-grating surface-emitting DBR lasers. The structure is an InGaAs/GaAs strained multiquantum-well. A modified fabrication process with a better control on the steps is used. A CW threshold current as low as 26 mA at a lasing wavelength of about 977 mm are reported. This is the first demonstration of CW operation for these lasers in any material system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Low-threshold CW operation of square-shaped semiconductor ring lasers (orbiter lasers)

The CW operation of square-shaped semiconductor ring lasers is demonstrated with a threshold current as low as 6 mA. The ring resonator consists of straight waveguides and four total reflection mirrors. The lasers are fabricated using Br/sub 2/ dry etching on an InGaAs/GaAs strained single-quantum-well graded-index separate-confinement heterostructure wafer. The low-threshold CW operation is due to the high differential gain of the wafer and the low-loss total reflection mirror.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Low-threshold CW operation of an erbium-doped fibre laser pumped at 807 nm wavelength

We report an erbium-doped fibre laser operating CW at a wavelength of 1555nm pumped at a wavelength of 807 nm, with a threshold launched pump power of 2.5 mW. This level corresponds to only 1 mW of pump power absorbed.

Low Threshold CW Operation GaInAsP/InP Mushroom Stripe Laser (MSL) Emitting at 1.27 µm

Low Threshold CW Operation GaInAsP/InP Mushroom Stripe Laser (MSL) Emitting at 1.27 µm