<title>Digital generation of high-quality periodic signals for use with acousto-optic modulators</title>

Abstract

Double ultrasonic beams acoustooptical modulators require high pre cisiorl driviri electric signals for stabile control of frequency rati() arid phase shift, High precision digital synthesis niethod has been developed for the generation of high quality periodic signals. Maximum frequency range of a synthesized waveforms is determined by the speed of avii.1abie RAM (Random Access Memory) and an available P/A converter. A computer-based digital function generator can generate any arbitrary type of signal in the frequency range deterniiried by the speed of PAM and the ..P/A converter. Frequency stability is determined by quartz clock of the P/A converter and is in the order of I /1OPeriodic waveforms can be synthesized, stored and then played continuously by looping through the RAM huffer I HTRODUCT I ON A new, h I gh prec i s i on d i gi ta 1 syntlies i s method has been developed for the generition of high quality periodic signals and some aousto--opticai appi ication is suggested. Maximum frequency rare of a synthesized waveform is determined by the speed of available RAM (Random Access Memory) and in available D/A converter. With a n-bit P/A converter one can get. S/N :: 6*n [dB] (for exampi e, for 8-hit P/A,dli). With the proposed method, high quality sinusoidal, square, trangular, pulse, pseudo--ratidoiii noise and other types of wayes can he generated. Analog signal generators suffer from a lack of 0-8194-1 070-5/92/$4.Q0 SPIE Vol. 1844 Acousto-Optics and Applications (1992)1 251 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/17/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx