InGaAlP Visible Light Laser Diodes Research Articles

Reliable High-Power Operation of InGaAlP Visible Light Laser Diodes with Strained Active Layer

Reliable high-power operation of transverse-mode stabilized InGaAlP laser diodes has been achieved with a selectively buried ridge waveguide (SBR) structure and a very thin (150 Å) In0.62Ga0.38P active layer. A strained In0.62Ga0.38P layer was employed in order to improve the temperature characteristics during high-power operation. An over 100 mW maximum output power was obtained. Operation current density was found to have a large effect on the device reliability. Lasers with a long cavity operate in a low current density, resulting in an increase in device lifetime. In the 600 µm long SBR lasers, stable continuous wave (CW) operation exceeding 1000 hours has been achieved with a 30 mW output at 50°C.

Highly reliable 100 mW operation of broad area InGaAlp visible light laser diode

The aging characteristics of broad area InGaAlP visible light laser diodes have been investigated. Asymmetric coatings and a highly p-doped cladding layer were employed. Highly reliable operation, as high as 100 mW for more than 2000 h has been realised at 15°C.

High-temperature operation of high-power InGaAlP visible light laser diodes with an In0.5+δGa0.5−δP active layer

High-power and high-reliable operation of transverse-mode stabilized InGaAlP laser diodes has been achieved by a selectively buried ridge waveguide structure with a thin (0.02 μm) active layer. A composition-shifted In0.5+δGa0.5−δP active layer was employed in order to improve the temperature characteristic. A maximum cw light output power of 54 mW was obtained for the laser with antireflection and high-reflection coatings. A high-power cw operation above 30 mW output power was maintained even at a 60 °C heat-sink temperature. Stable cw operation exceeding 1000 h has been achieved for 20 mW output power at 50 °C.

New window-structure InGaAlP visible light laser diodes by self-selective Zn diffusion-induced disordering

The behavior of Zn diffusion in InGaAlP double heterostructures during a second metalorganic chemical vapor deposition (MOCVD) growth was investigated, and it found that the behavior of Zn diffusion strongly depends on the presence of an n-GaAs capping layer. A process for InGaAlP window-structure InGaAlP laser diodes was designed using this unique diffusion behavior and disordering of a natural superlattice. A window structure realizing a high power operation was successfully fabricated. A maximum output power above 80 mW was obtained for continuous wave (CW) operation, and 400 mW for pulsed operation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High-power operation of heterobarrier blocking structure InGaAlP visible light laser diodes

Heterobarrier blocking structure InGaAlP visible light laser diodes employing a thin active layer (0.04 μm) and asymmetry coatings have been fabricated. The high light-output power operation with this heterobarrier blocking structure was investigated. The light-output power versus cw current curve was linear up to 43 mW and a maximum light output power of 51 mW was obtained. A high-power operation such as 20 mW was maintained at 40 °C. Stable oscillation in the fundamental transverse mode was obtained up to 30 mW. These results show that this heterobarrier blocking structure supplies a sufficient current confinement effect even under a high-light output power operation.

High-power CW operation of broad area InGaAlP visible light laser diodes

Broad area InGaAlP visible light laser diodes with antireflection and high-reflection coatings have been fabricated. High power cw operation above 300 mW was obtained at 2°C heat-sink temperature. This value corresponded to a light power density of 2.7 MW/cm2. The far field pattern showed a single lobe shape for output power up to 100 mW.

Short-wavelength (638 nm) room-temperature CW operation of InGaAlP laser diodes with quaternary active layer

638 nm room temperature (25°C) CW operation was successfully achieved by InGaAlP visible light laser diodes with a quaternary active layer. A transverse mode stabilised selectively buried ridge-waveguide structure was fabricated by metalorganic chemical vapour deposition. The threshold current was 100 mA at 25°C and CW operation was attained at up to 50°C. The oscillation wavelength was the shortest for room temperature CW operations of laser diodes ever reported.

Effect of facet coating on the reliability of InGaAlP visible light laser diodes

Effect of facet coating on the reliability of InGaAlP visible light laser diodes is investigated. Uncoated InGaAlP laser diodes showed facet oxygen related degradation after aging as the gradual degradation mode. Such degradation was drastically suppressed by facet coating. InGaAlP laser diodes with Al2O3-coated facets have operated for more than 2500 h at 50 °C at an optical output power of 3 mW without any significant degradation.

CW operation at - 10°C for InGaAlP visible light laser diodes grown by MOCVD

CW operation at - 10°C for InGaP/InGaAlP double heterostructure (DH) laser diodes has been achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapour deposition using methyl metalorganics as the source of group III elements. Under room-temperature pulsed operation, the lasing wavelength was 663 nm and the lowest threshold current density was 7.8 kA/cm2. The CW characteristic temperature T0 was 63 K at around -30°C.