Porous gallium phosphide: challenging material for nonlinear‐optical applications

Abstract

PACS 42.25.Lc, 42.65.Ky, 78.55.Mb, 82.45.Vp Electrochemically produced porous GaP layers demonstrate strong non-Rayleigh light scattering in visible range. Moreover, (110) porous GaP layers exhibit in-plane birefringence. Both properties offer much promises for enhanced nonlinear-optical processes. We report experimental studies of spectral and orientation dependences of the second-harmonic generation in (110) and (111) porous GaP layers. An order of magnitude increase of the second-harmonic intensity was found in the strongly scattering porous GaP layers in comparison with monocrystalline GaP. The spectral dependence of the second-harmonic intensity was discussed in terms of the phase matching and light localization phenomena.

Macroporous Semiconductors

“… Practically all applications discussed so far use porous Si. Microporous Ge might find applications [ 30 , 175 ] but so far very little has been proposed with respect to applications of porous III-V’s [ 176 , 177 ]. Some proposed applications, while perfectly viable, are rather impractical.…”

“…The effect is beyond doubt, but needs yet to be demonstrated. Moreover, porous III-V crystals like GaP (and possibly also II-VI crystals) may also have very unusual non-linear properties as demonstrated in [ 176 , 177 ] for porous GaP, where a more than 100 fold increase of the second harmonic production was observed. This example serves to point out that so-called meta-materials can be made with porous semiconductors having properties that are so unusual that it is not surprising that they have not yet been exploited.…”