Showing papers by "Leo W. Hollberg published in 1988"
TL;DR: In this paper, the frequency of a laser is stabilized to a separate Fabry-Perot reference cavity using resonant optical feedback and can be modulated efficiently at frequencies related by rational fractions to the free-spectral range of the reference cavity.
Abstract: We find that using the technique of optical feedback locking, to narrow semiconductor linewidths, does not sacrifice the ability to modulate the laser’s frequency via the injection current. The frequency of a laser is stabilized to a separate Fabry–Perot reference cavity using resonant optical feedback and can be modulated efficiently at frequencies related by rational fractions to the free‐spectral range of the reference cavity. This system can provide an array of narrow‐linewidth, frequency‐stable laser lines and shows promise for applications in frequency‐division‐multiplexed coherent communications, as well as laser frequency control and precision measurement systems.
61 citations
Patent•
18 Oct 1988
TL;DR: In this paper, an optical method and apparatus for stabilizing the frequency of semiconductor lasers is described. But the optical geometry is configured such that the output from the resonator is fed back to the laser only when the laser frequency matches or substantially matches the resonance frequency.
Abstract: An optical method and apparatus is disclosed for stabilizing the frequencyf semiconductor lasers. The basic system includes only the optical elements of a conventional semiconductor laser optically coupled to a separate, external resonator having an optical cavity with a particular resonance frequency. The optical geometry is configured such that the output from the resonator is fed back to the laser only when the laser frequency matches or substantially matches the resonance frequency. In other disclosed embodiments, optical electronic feedback loops are used to modulate the laser injection current to stabilize the frequency and to adjust the phase of the optical feedback signal.
49 citations
01 Jan 1988
TL;DR: In this paper, an experiment was conducted to investigate the effect of laser line-narrowing on the performance of an optically pumped cesium beam frequency standard, and the results showed that line narrowing was necessary to achieve beam shot noise limited performance.
Abstract: An experiment has been conducted to investigate the effect of laser line-narrowing on the performance of an optically pumped cesium beam frequency standard. A two laser scheme (4-+4'u for optical pumping and 4+5'7t. for detection) was used and the lasers were either frequency locked to Cs saturated absorption features in an external cell or linenarrowed by optical feedback from an external Fabry'Perot cavity [l]. Relative to the frequency stabilization to the saturated absorption the line-narrowing on the detection laser produced a large improvement (+14dB) in the signal-to-noise ratio (S/N). However, line-narrowing on both pump and detector lasers was necessary to achieve beam shot noise limited performance. The S/N and line Q achieved in these experiments should result in a clock stability of uy (~)=3-5~10-'~ T-'/' [21.
10 citations