Enhanced Temperature Characteristics of InGaAs/InAlGaAs Multi-Quantum-Well Lasers on Low-In-Content InGaAs Ternary Substrates

Abstract

Temperature characteristics of multi-quantum-well lasers on InGaAs ternary substrates are investigated. By using InAlGaAs barriers and low-In-content InGaAs substrates, the characteristic temperature of the laser can reach as high as 150 K between 25 and 85 C due to the enhancement of the material gain. Calculated characteristic temperatures are in good agreement with those obtained by experiment, showing the validity of the results presented here. #

Microscopic design of GaInNAs quantum well laser diodes on ternary substrates for high-speed and high-temperature operations

“…The other approach is to grow QW lasers on GaInAs or quasi-GaInAs substrates. [5][6][7][8][9][10] The larger the In content of the substrate ͑x sub ͒ is, the smaller the strain of the well layer becomes. Recently, we fabricated GaInAs/ GaInAs QW lasers on low-In-content GaInAs ͑x sub = 0.1͒ substrates with the operating wavelength of 1.28 m and the characteristic temperature T 0 of 130 K, 8 although large strain ͑ Ͼ 2%͒ was still required in the well layer.…”

“…It is difficult to fabricate In-rich GaInAs substrate and the material gain of QWs is reduced if x sub is large. 9 Further, a highly strained well layer makes it difficult to grow high-crystal-quality QWs and affects long-term device reliability.…”

“…3,5,9 However, the treatment forces us to use phenomenalogical fitting parameter. Furthermore, important physical phenomena, such as absorption peaks due to excitons and bandgap renormalization cannot be reproduced.…”

“…3,5,9 This approach gives a simple explicit formula for the material gain, and has therefore been widely used for QW designs. However, the treatment leads to the incorporation of a phenomenalogical parameter, relaxation time, which is fitted from experimental results to explain the broadening of gain spectrum originating from carrier-carrier scattering Shear deformation potential c 11 , c 12 Stiffness constants w Strain in xy plane T Temperature N Carrier density effects ͑many-body effects͒.…”

“…Usually, the material gain of QWs on GaInAs substrates is larger for smaller values of x sub due to the large ⌬E c . 5,9 However, the value of the material gain is not so changed. If the strain is constant, QWs with smaller x sub have a larger N mole fraction.…”