Accession Number : AD0696579

Title :   GAS LASER DISCHARGE NOISE AND ITS EFFECT ON THE LASER OUTPUT,

Corporate Author : CALIFORNIA INST OF TECH PASADENA QUANTUM ELECTRONICS LAB

Personal Author(s) : Yoh,James

Report Date : MAY 1969

Pagination or Media Count : 146

Abstract : A large portion of the noise in the light output of a laser oscillator is associated with the noise in the laser discharge. The effect of the discharge noise on the laser output has been studied. The discharge noise has been explained through an ac equivalent circuit of the laser discharge tube. The discharge noise in a laser comes from spatial fluctuations in the electron density, the inverted population density and the dielectric permittivity of the laser medium. These fluctuations influence the resonance condition of the laser cavity. When the fluctuation in the dielectric permittivity of the laser medium is a longitudinally traveling wave, the resonant frequency is modulated. The discharge noise has been analyzed by representing the laser discharge tube by an equivalent circuit consisting of a series rho-LC circuit, which represents the discharge region, in parallel with a capacitance C', which comes mainly from the stray wiring. The equivalent inductance and capacitance of the discharge region have been calculated from the values of the resonant frequencies measured on discharge currents, gas pressures and lengths of the positive column for helium, neon, xenon and helium-xenon discharges. The ac equivalent circuit of the laser discharge has been shown analytically and experimentally to be applicable to analyzing the internal discharge noise. (Author)

Descriptors :   (*GAS LASERS, NOISE(RADIO)), GAS DISCHARGES, ELECTRON DENSITY, DIELECTRIC PROPERTIES, RARE GASES, THESES

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE