Measurement of spontaneous emission factor for vertical-cavity surface-emitting semiconductor lasers

Using a method based on measurement of modulation frequency harmonics, we have determined experimentally the spontaneous emission factors of GaAs-AlGaAs QW vertical cavity surface-emitting semiconductor lasers with square windows of widths 10, 15, and 30 μm. The values obtained are of the order 10/sup -4/ and scale as the reciprocal of the window width. We have also assessed the reliability and accuracy of the modulation frequency harmonic measurement technique by comparison with the prior technique based on curve fitting to the light-current characteristic.