High-modulation-depth and short-cavity-length silicon Fabry–Perot modulator with two grating Bragg reflectors

We propose a silicon Fabry–Perot planar waveguide modulator structure consisting of two Bragg reflectors to form the cavity. The Bragg reflectors are nanoscale trenches in the waveguide fabricated using electron beam lithography and reactive ion etching. Compared to conventional waveguide modulator designs, large modulation depth can be achieved with much smaller modulator length using high-finesse Fabry–Perot cavity, leading to much less loss and higher speed. This modulator design can also be utilized as an externally tunable spectral filter. © 1996 American Institute of Physics. @S0003-6951~96!04702-6#