We present results on the first all-semiconductor, vertical Fabry-Pero
t-cavity optical transmission modulator. This device combined mechanic
ally stable strained and unstrained (In,A1,Ga)As multilayers to achiev
e operation at 1.06 mum. Transmission-mode operation allows the resona
nt wavelength of the cavity to be finely tuned by varying the angle of
incidence, providing, for the first time, a means of compensating for
small inaccuracies in growth parameters. Using the modulator in doubl
e-pass operation with a corner-cube retroreflector, we demonstrate a t
unable reflectance modulator with a fractional modulation of 25% at 3-
V bias, suitable for applications in free-space communication.