An acousto-optic, Bragg-type modulator/beam deflector is fabricated in a waveguide material which has refractive index n = 2.2 and an acoustic velocity υa = 2800 m/s. (a) If the modulator is to be...

An acousto-optic, Bragg-type modulator/beam deflector is fabricated in a

waveguide material which has refractive index n = 2.2 and an acoustic velocity υa = 2800 m/s.

(a) If the modulator is to be operated at an acoustic frequency of 100 MHz

what should be the spacing between the interdigitated metal fingers of

the acoustic transducer? Draw a sketch of the transducer fingers and

label the spacing for clarity.

(b) What is the angle through which the optical beam will be deflected if the

light source is a He-Ne laser with wavelength λ0 = 6328 A?˚