Figure 7.1 depicts the scheme of a feedback loop that underlies many servo systems used to stabilize the frequency of optical lasers. This chapter presents examples of the ways this stabilization can be realized. Basically, the scheme consists of a wavelength comparator that generates the error signal for the feedback loop by processing a reference wavelength and the actual wavelength of the laser. This error signal is fed back to the loop, and a transducer is employed to change the laser cavity slightly to bring the error in frequency to zero.
Laser Wavelength Stabilization