Integrated-optic spectrum analyzer(Invited Paper)

This paper describes the integrated-optic implementation of a Bragg spectrum analyzer that employs the interaction between a coherent optical guided wave and a surface acoustic wave to determine the power spectral density of the input. The integrated-optic spectrum analyzer (IOSA) consists of an injection laser diode, a thin-film optical waveguide, waveguide lenses, a surface-acoustic-wave (SAW) transducer, and a linear detector array with CCD readout. Design principles are given for selecting component parameters such as optical beam width, detector cell size, lens aperture and focal length, and acoustic transducer design so as to obtain specific RF resolution, spurious level, and signal-to-noise ratio. Design parameters are presented for a 750-1250-MHz spectrum analyzer with a resolution of 4 MHz and a 40-dB dynamic range. Also described in the paper is the development of the state-of-the-art component technology for the spectrum analyzer.