Stabilisation of carbon dioxide lasers using the Stark effect

Abstract

A large number of Stark-tuned molecular absorptions have been investigated as possible references for Stark stabilisation of waveguide CO2 lasers. A set of potentially useful absorptions have been selected and transition tuning rates, absorption coefficients, and electrical breakdown characteristics have been measured for a number of these. A discussion of the optimisation of a Stark stabilisation system is given. Predictions of absorptions that will be useful in stabilising isotopic lasers are also reported.

Saturation dip measurements of pressure broadening in CH3F

“…(iii) The collision cross section is dependent on the relative velocity of the colliding Thus the DC voltage tunes components of the Q ( 2 , 2 ) transition to the laser frequency while the AC modulation allows the feedback loop to be completed, locking the iaser to the Q ( 2 , 2 ) component. This arrangement has two significant advantages over many other locking systems: the modulation frequency is high which avoids noise problems, and there is no residual FM modulation on the laser (Rackley and Butcher 1983). After stabilization of the laser using SCI, the DC Stark voltage was tuned which ultimately tuned the laser frequency.…”