A folded-type integrated-optic spectrum analyzer using butt-coupled chirped grating lenses

A folded-type integrated-optic spectrum analyzer (IOSA) using reflection-type chirped grating lenses butt-coupled to a LiNbO
3
waveguide Bragg cell is presented. The lenses can be easily fabricated by the well-established planar process, and the IOSA has good performance as well as a reduced device length. The spectrum analyzer function of 4.0 MHz resolution in 95-345 MHz RF frequency range is demonstrated.