Asynchronously modulated waves in a ring laser cavity.

When modulated through the harmonic motion of one mirror, the counterpropagating waves in a ring laser oscillate out of phase. A solution to the wave equation is presented that satisfies both the time-dependent boundary condition and the resonance condition. This theoretical prediction is confirmed experimentally to leading order in terms that are inversely proportional to the speed of light. The method of solution is applicable to arbitrary phase modulation at more than one spatial location in the cavity. Potential uses include the reduction of the locking problem in ring lasers and the testing of higher-order kinematic effects in the theory of relativity.

Noise waveforms with repetitive phase and nonrepetitive amplitude.

By use of frequency-shifted feedback lasers, noise with a stationary amplitude and a periodically stationary phase is generated. The ensemble-averaged time correlation function is periodic, whereas the power spectrum is broadband, resulting in a waveform that does not obey the Wiener-Khintchine relations. An application to multiple-access communications is discussed.