Computer control of broadly tunable lasers: conversion of a color center laser into a high resolution laser...

The conversion of a commercial color center laser (Burleigh FCL-20) into a computer-controlled high resolution laser spectrometer is described. The techniques and methods developed are generally useful for the control of any broadly tunable cw laser. Superposition of several kinds of computer-controlled feedback upon a table look-up (feed-forward) procedure is used for each of the control elements. This feedback removes the coupling between the tuning elements and eliminates the effects of the nonideal properties of the control elements such as PZT hysteresis and creep. The resulting spectrometer is capable of acquiring high resolution (instrumentally limited by free running laser jitter to ~3 MHz) spectra which can be precisely measured (~0.0003 cm(-1)). The spectrometer has routinely made continuous single-mode scans of 30,000 points separated by 10 MHz covering 10 cm(-1).