We wish to design a GaP electro-optic phase modulator as shown below for operation at 6300 A wavelength. ˚ (a) What is the minimum thickness (t) required in the waveguiding layer if the carrier...

We wish to design a GaP electro-optic phase modulator as shown below for

operation at 6300 A wavelength. ˚

(a) What is the minimum thickness (t) required in the waveguiding layer if

the carrier concentrations are N2 = 1 × 1015 cm−3 and N3 = 3 × 1018

cm−3?

(b) How large a voltage (V) can be applied without producing electrical

breakdown?

(c) If this voltage is applied, how long (L) must the device be to produce a

phase shift of π radians in the transmitted light wave? Assume the incident light is polarized in the Y direction. For GaP:

Ec (critical electric field for breakdown): 5 × 105 V/cm, r41 (electro-optic coefficient for the above orientation): 5 × 10−11 cm/V, m∗ (effective mass): 0.013m0. n = 3.2.