Optical loss in large optical cavity 650 nm lasers

Using a segmented-contact method, we have measured the optical mode loss in a series of AlGaInP 650 mn large optical cavity laser diodes with cladding layer thicknesses of 1.0, 0.5 and 0.3 mum. For the thinnest cladding layer the loss is 24 cm(-1), greater than the other devices and by comparison wi th transfer matrix calculations we show that this is due to penetration of the mode into the outer GaAs layers. The results show that the cladding thi ckness can be reduced to about 0.5 mum without significant increase in loss and threshold current and this could be beneficial in reducing, the electr ical and thermal resistance of the cladding layer in high power structures.