Thomas Ehrenreich

A laser diode array pumped cesium vapor laser

An efficient Cesium vapor laser pumped with a continuous wave narrowband Laser Diode Array (LDA) has been demonstrated. To obtain a high lasing efficiency, it is necessary to narrow the linewidth of the pumping LDA to match the Cs atom absorption line. An external cavity with holographic grating was used to narrow the linewidth of a commercially available LDA to a value of 11 GHz that matches the Cs vapor absorption line broadened by a buffer gas at atmospheric pressure. The developed pump source was used for pumping a Cs vapor laser, which operated at 894 nm. Preliminary experiments yielded 400 mW output power and about 20% slope efficiency. The laser efficiency can be significantly increased by optimizing the cell and cavity design and matching the pump beam to the cavity mode size.

Highly efficient cesium vapor laser

An extensive development of high power lasers for military and civilian applications has resulted in several highly successful laser systems based on chemical lasers. These lasers have some undesirable features, most notably their use of dangerous chemicals and excessive size. Alternative laser systems such as solid state, fiber lasers and semiconductor lasers have not achieved the necessary powers and beam quality. In this paper we present the results of our work on optically pumped cesium vapor laser development. We demonstrated efficient cesium laser operation at wavelength 894 nm with diode laser pumping. The measured optical efficiency was more than 32% with an overall electrical to optical efficiency of 15%. With an improved cavity design and narrowband pump source we have demonstrated Cs laser with slope efficiency of 81% and overall optical efficiency of 63%. This laser can be scaled to higher powers by increasing the volume of the active medium and number of narrowband pump diode lasers.

Optically pumped alkali lasers

Optically pumped alkali vapor lasers have been developed during last several years. Efficient operation of Cesium, Rubidium and Potassium vapor lasers has been demonstrated. Laser slope efficiencies higher than 80% have been achieved. In this paper we present the latest achievements in this field, discuss the main directions and problems in high power alkali lasers development and possible solutions of these problems.

Cs laser for homeland and national security

An efficient Cs vapor laser pumped by a diode laser has been demonstrated. This laser can be scaled to high powers and can be used for missile defense and for MANPADS protection.

Alkali Lasers for Homeland and National Security

Alkali vapor lasers show the promise of demonstrating diffraction limited high power in the near and mid IR. These lasers could be used for missile defense and for protection from Man Portable Air Defense Systems.