Accession Number : ADA017185

Title :   The Effect of Intracavity Subharmonic Phase Modulation on a Nd:YAG Laser.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

Personal Author(s) : Plummer,William W. , Jr

Report Date : MAR 1965

Pagination or Media Count : 130

Abstract : A Nd:YAG laser propagating in the TEM sub 00 mode was phase modulated by an intracavity lithium niobate crystal that was driven at a subharmonic frequency equal to one half the frequency difference between the free-running modes. Experimental results showed that the subharmonic frequency caused low amplitude subharmonic modes to be injected by single-pass modulation into the scanning Fabry-Perot interferometer display of the free-running modes, which otherwise remained unperturbed. When a spectrally impure RF drive, primarily composed of the sub-harmonic and twice this frequency, was allowed to phase modulate the laser, mode-locking resulted because of the residual harmonic power in the signal. As phase-state switching randomly occurred, subharmonic modes either appeared or disappeared in the interferometer display of the phase-locked modes. This effect was theoretically shown to be a result of the phase relationship between the subharmonic frequency of the RF drive and the electric field in the cavity, a relationship that changed by pi/2 radians whenever phase-state switching occurred.

Descriptors :   *Mode locked lasers, *YAG lasers, *Phase modulation, Neodymium, Doping, Tuning devices, Frequency multipliers, Laser cavities, Test methods, Lithium compounds, Niobates, Absorption spectra, Fluorescence, Mathematical analysis, Radiofrequency pulses, Interferometry, Theses

Subject Categories : Lasers and Masers
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE