THERMAL-BEHAVIOR OF TENSILE-STRAIN INGAASP-INP LASERS WITH VARYING RIDGEWIDTH

The thermal behavior of tensile-strain InGaAsP-InP laser diodes with v arying ridgewidth is investigated experimentally. The temperature rise during continuous-wave (CW) operation was determined by comparing CW light-current (L-I) curves with short-pulsed (L-I) curves at different substrate temperatures. It is shown that the thermal impedance (R) ov er bar depends strongly on the width io of ridge and that this effect is different before or after threshold. In the first case, (R) over ba r decreases with the increase of the ln(w) and in the second case, (R) over bar increases with the increase of l/w. However, the wider the r idge, the lower the CW maximum operating temperature because of its hi gher temperature dependence of dI(th)(T)/dT.