Abstract
This paper describes a new, simple method for obtaining the output- and frequency-stabilized single mode output of an internal-mirror He–Ne laser (λ=633 nm). The total back-beam intensity is detected with a silicon photodiode and the photodiode current is converted into a voltage signal. A voltage proportional to the difference between the voltage signal and a stable dc reference voltage is applied to a laser discharge current regulation circuit which controls the change in the laser tube length due to thermal contraction. As a result, the laser output power and frequency are stabilized at the same time. A relative output stability of ±0.12% and a relative frequency stability of ±4×10-9 were obtained over a period of 10 minutes or longer.
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