Queue Design and Implementation Based on Service Level of NQS.

A laser frequency drift control device for an electrically powered, integral electrode and end-mirror, gas laser tube is disclosed. The control device includes a resistance and transistor heater assembly, which is electrically connected to be powered by the discharge current of the laser tube and thermally coupled to an end-mirror to heat the same, a thermal sensor coupled to the end-mirror to be heated for the purpose of obtaining temperature feedback, and a control circuit which varies heating of the end-mirror in accordance with the temperature feedback. LEDs provide visual feedback as to operation of the heater assembly to permit adjustment thereof. A method of controlling temperature variation induced laser frequency drift is also disclosed.