Stable Lateral Mode Operation Research Articles

High-power high-efficiency 660-nm laser diodes for DVD-R/RW

A kink mechanism in 660-nm laser diodes (LDs) has been studied experimentally. The experiments revealed that the main origin of the kink is a refractive index change due to heat generation in the stripe portion, and the kink power can be increased by improving the temperature characteristics of the LD. A newly developed LD, based on this result, shows stable lateral mode operation up to 190 mW at 80/spl deg/C. This is the highest power recorded among narrow stripe LDs with a wavelength of 660 nm. This LD is suitable for the next generation of high-speed (8x-) DVD-R/RW drives necessitating 140 mW class LDs.

Thermal Rollover around 460 mW Observation in Single-Lateral Mode 780 nm Laser Diodes with Window-Mirror Structure

Narrow stripe 780 nm window-mirror structure laser diodes (LDs) with and without a leakage current blocking structure in the window-mirror region were studied in terms of catastrophic optical degradation (COD) at facets. It was experimentally proved that a non-leakage-current-injection structure using proton implantation was effective in improving the COD level even in LDs with a window-mirror made by multi quantum well disordering. The thermal rollover phenomenon at around 460 mW at room temperature was observed in this LD. This is the highest output power recorded among narrow stripe LDs with a wavelength of 780 nm. Stable lateral mode operation up to 350 mW was also realized. This LD is suitable for the next generation of high speed (48 ×-) CD-R/RW drives necessitating 250 mW class LDs.

Over 200-mW operation of single-lateral mode 780-nm laser diodes with window-mirror structure

The high-power operation of the lateral mode stabilized 780-nm AlGaAs laser diode (LD) with the window-mirror structure has been achieved. The stable lateral mode operation up to 250 mW is realized. This is the highest power record among the narrow stripe LDs with the wavelength of 780 nm. This LD is suitable for the next generation high-speed (16-24/spl times/) CD-R/RW drives needing 200 mW class LDs.

Highly reliable and stable-lateral-mode operation of high-power 0.98-μm InGaAs-InGaAsP lasers with an exponential-shaped flared stripe

A 0.98-/spl mu/m InGaAs-InGaAsP-GaAs strained quantum-well (QW) laser with an exponential-shaped flared stripe is proposed for high-power, highly reliable operation. The stripe width is wider at the front facet to reduce the optical density by widening the spot size. The stripe width is narrower at the rear facet for stable lateral-mode operation. The stripe width in the transient region is varied exponentially along the cavity for smooth mode transformation. We showed that this structure expands the spot size effectively without any deterioration in stable lateral-mode operation. The kink-occurrence output power is determined only by the stripe width at the rear facet, and the spot size at the front facet is a function only of the stripe width at the front facet. The maximum output power is 40-60% higher than that of ordinary straight-stripe lasers for the same kink-occurrence output power. Testing at 150 mW showed stable operation with an estimated lifetime of more than 200000 h at 25/spl deg/C.

Circular beam, high power operation of 0.98 µmInGaAs/InGaAsP lasers with a tapered waveguide spot-size expander

A 0.98 µm InGaAs/InGaAsP strained quantum well laser with a laterally tapered waveguide spot-size expander is demonstrated to achieve highly reliable and stable lateral mode operation. This laser, which has a 0.8 µm wide ridge-neck at the facet, showed a linear L-I curve up to 340 mW, with circular and narrow beam divergence of 10° × 15°.

Semiconductor integrated étalon interference laser with a curved resonator

A semiconductor interferometric laser with a resonator having curved and straight segments is reported. Interference is caused by internal reflection at the junction discontinuity between curved and straight segments due to a slight difference between the wave propagation constants. Lateral mode stability is provided by the fabrication of a buried heterostructure type laser cavity. The outstanding features of the laser are (1) very stable single longitudinal mode and stable lateral mode operation, and (2) a wavelength locking range of up to 23 °C within which the wavelength changes at a rate of 0.5–0.6 Å/°C.