Accession Number : ADA131156

Title :   Phase Conjugation in a Ring Laser Cavity.

Descriptive Note : Final rept. 1 Sep 79-31 Aug 82,


Personal Author(s) : Diels,Jean-Claude M

PDF Url : ADA131156

Report Date : 30 Jun 1983

Pagination or Media Count : 72

Abstract : We investigate the dynamics of phase conjugation by degenerate four wave mixing (DFWM) inside a laser cavity. This problem is shown to be important in connection with (a) protection of a high power laser against self focusing and (b) development of a new type of laser gyro. Our theory demonstrates that fast optical and temporal phase conjugation by DFWM is incompatible with large (approx. or equal to 1) reflection coefficients. Therefore, it appears to be better to implement DFWM for the coupling of the two counterpropagating pulses in a ring laser, rather than as an end cavity reflection of a linear laser. Various schemes and media were investigated (sodium vapor, amplifier-absorber, jet, saturable absorber thin jet, saturable absorber coupled by evanescent wave). The largest nonlinear third order susceptibility was found in the amplifier jet. Study of fast dynamics of DFWM in an absorber led us to develop a ring laser producing pulses shorter than 55 fs, tunable in a 20 nm range. The measurements of DFWM inside the absorber jet of a ring laser are the basis of a new diagnostic method to measure very short (less than or approximately 100 fs) relaxation rates. (Author)

Descriptors :   *Ring lasers, *Laser cavities, *Wave propagation, Pulses, Gyroscopes, Theory, Reflection, Internal, High power, Coefficients, Coupling(Interaction), Linear systems, Absorption

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE