91Ó°ÊÓ

A GaAs crystal with refractive index \(n=3.6\) and electro-optic coefficient \(\mathrm{r}=1.6 \mathrm{pm} / \mathrm{V}\) is used as an electro-optic phase modulator operating at \(\lambda_{4}=1.3 \mu \mathrm{m}\) in the longitudinal configuration. The crystal is \(3 \mathrm{~cm}\) long and has a \(1-\mathrm{cm}^{2}\) cross-sectional area. Determine the half-wave voltage \(V_{r-}\) the transit time of light through the crystal, and the electric capacitance of the device (the low-frequency dielectric constant of GaAs is \(\epsilon / \epsilon_{0}=13.5\) ). The voltage is applied using a source with \(50-\Omega\) resistance. Which factor limits the speed of the device, the transit time of the light through the crystal or the response time of the electric circuit?

A GaAs crystal with refractive index \(n=3.6\) and electro-optic coefficient \(\mathrm{r}=1.6 \mathrm{pm} / \mathrm{V}\) is used as an electro-optic phase modulator operating at \(\lambda_{w}=1.3 \mu \mathrm{m}\) in the longitudinal configuration. The crystal is \(3 \mathrm{~cm}\) long and has a \(1-\mathrm{cm}^{2}\) cross-sectional area. Determine the half-wave voltage \(V_{r-}\) the transit time of light through the crystal, and the electric capacitance of the device (the low-frequency dielectric constant of GaAs is \(\epsilon / \epsilon_{0}=13.5\) ). The voltage is applied using a source with \(50-\Omega\) resistance, Which factor limits the speed of the device, the transit time of the light through the crystal or the response time of the electric circuit?