Measurement of transverse electric and transverse magnetic spontaneous emission and gain in tensile strained GaInP laser diodes

We have measured the modal gain and spontaneous emission spectra of a 0.8% tensile-strained GaInP laser structure in transverse electric (TE) and transverse magnetic (TM) polarizations by analysis of the single-pass amplified spontaneous emission from the end of a segmented-contact structure. The absolute values of the true spontaneous emission rates have been determined for both polarizations. Data for the TEy and TM peak gain as functions of the total intrinsic radiative current can be fitted with the usual logarithmic relation with a transparency current density of 99 A cm−2 and with the (electron–light-hole) TM/TEy gains in the ratio 4:1 as predicted from the oscillator strengths. Spontaneous emission into the TM modes accounts for 48% of the total radiative current.