ELECTRONICS RESEARCH PROGRAM. OPTICAL MASER STUDIES.
Abstract
Observation of the near field and far field patterns of a ruby laser operated near threshold is described. In these observations, the beam diffraction effect predicted for diffraction by a small elliptically shaped aperture has been observed. This effect is a 90-degree rotation of the elliptical figure. This result indicates that the far field light intensity distribution need not be identical with the near field distribution. Experimental results are presented that show the presence of many axial modes in the output of the ruby laser operated very close to threshold. Multimode operation is found to be the rule, even when the output of the laser appears as a regularly spaced, exponentially damped series of spikes. Theoretical analysis of the laser oscillations has indicated that the initial laser spike transient should damp out, leaving only the cw oscillation of the laser. This effect has been observed for the first time in a ruby laser operated very close to threshold. In many cases, the initial train of laser pulses appears to damp out and approach a cw level of oscillation. A cw beat frequency is often found to coincide with the cw light output. Thus, the oscillations of the ruby laser are in agreement with observations of other solid-s/atelasers and confirm the theoretical pedictions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 25, 1963
- Accession Number
- AD0426013
Entities
People
- M. Birnbaum
- T. L. Stocker
Organizations
- The Aerospace Corporation