Photoluminescence measurements of InP-based double-heterostructure crystals with high-power 980-nm laser excitation and a thin Si-plate filter

We have measured photoluminescence (PL) spectra of InP/InGaAsP/InP-type a double-heterostructure (DH) for optical devices under irradiation by a high-power laser diode emitting at 980 nm (98LD). We observed the PL spectra from 1.0 μm, after filtering the 98LD light with a thin Si-plate. The measurable wavelength region of PL spectra becomes shorter by about 0.1 μm than that for conventional YAG laser excitation. We have examined precisely the relationship between the 98LD emitting wavelength and the Si-plate thickness, and confirmed that the Si-plate thickness plays an important role in widening the measurable wavelength region. Using the developed system, we have observed 1.1-μm-DH as well as 1.05-μm-DH crystals, which cannot be measured by the conventional system. Almost all DH structures fabricated on the InP substrate can be characterized by using the newly developed system.