Injection lasers

AQGa As grown on GaAs is used for the preparation of light-emitting diodes (LEDs), injection lasers and... 

Early injection lasers were small rectangular parallelepipeds made by cutting a wafer of GaAs. Feedback was provided by mirrors polished on two edges or by cleaving. The wafer had ap—n junction incorporated into it and broad area or stripe contacts were provided. Laser stmctures have since evolved to satisfy a wide range of appHcation specific requirements. 

Several practical applications of hydrogen neutralization of impurities in compound semiconductors are described, including waveguiding, the lateral confinement of carriers for injection lasers, and the generation of resistive regions. Intentional hydrogenation has also been used to fine tune the properties of field-effect transistors. Finally, some remaining problems are identified. 

Kam Y. Lau and Amnon Yariv, High-Frequency Current Modulation of Semiconductor Injection Lasers... 

Baba, T., Fujita, M., Sakai, A., Kihara, M., and Watanabe, R., 1997, Lasing characteristics of GalnAsP/InP strained quantum-well microdisk injection lasers with diameter of 2-10 pm, IEEE Photon. Technol. Lett. 9(7) 878-880. 

Fujita, M., Sakai, A., and Baba, T., 1999, UltrasmaU and ultralow threshold GaliiAsP-lnP microdisk injection lasers design, fabrication, lasing characteristics, and spontaneous emission factor, J. Select. Topics Quant. Electron. 5(3) 673-681. 

Uses. In the manufacture of semiconductors, injection lasers, and solar cells in the manufacture of glass, graphite, and cathode oscillographs in metal alloys to prevent corrosion and metal fatigue... 

Thin films (qv) of vitreous silica have been used extensively in semiconductor technology. These serve as insulating layers between conductor stripes and a semiconductor surface in integrated circuits, and as a surface passivation material in planar diodes, transistors, and injection lasers. They are also used for diffusion masking, as etchant surfaces, and for encapsulation and protection of completed electronic devices. Thin films serve an important function in multilayer conductor insulation technology where a variety of conducting paths are deposited in overlay patterns and insulating layers are required for separation. 

Another quaternary in this system is Ini 3,(ALi Gai- ) v As, which can be grown lattice matched to InP substrates. These materials are grown by MOCVD using the precursors cited above with the addition of TMA1. Recently, this quaternary has shown promise for the growth of advanced high-performance injection lasers operating... 

Much has been learned in the thirty-five years since the demonstration of the first GaAs injection lasers [1,2], The main lesson from that period is that defect-free material is needed, hi the 1970s MITI set up a successful five year crash programme to make zero-defect GaAs. The reason behind the zero defect goal for diode lasers is that defects cause emission line broadening, and the threshold current for an injection laser is directly proportional to the emission linewidth. Excitons in semiconductors are very fragile. They can be easily destroyed, or have their linewidth broadened by crystal lattice disruptions of any sort. 

Today, the most advanced GaN-based injection laser by far is produced at Nichia Chemical by Shuji Nakamura s group [3], Their GaN material, from which the first lasers were fabricated, had 1010 defects/cm2 [4], Nevertheless, CW operation at 20°C has been demonstrated for many thousands of hours. The performance of these lasers flies in the face of conventional wisdom. 

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