Bulk semiconductor lasers at submillimeter/far infrared wavelengths

Abstract

A p-Ge laser operating at submillimeter wavelengths in Voigt configuration using a regular permanent magnet. The invention is improvement over prior art Ge Lasers which use superconducting magnets that require liquid helium to cool the magnets along with the Ge crystal. Although the subject invention requires cooling(refrigerant) of the Ge crystal itself, it does not need liquid helium. The permanent magnet can be Nd.sub.2 Fe.sub.14 B. The emissions using the novel invention were observed over a wider range of electric-field magnitude in Voigt configuration at a given magnetic field as compared to that of the prior system. The free space beam profile of the subject invention is Gaussian. The emission-strength of the subject invention is sufficient between 4 and 10K that a closed-cycle refrigerator can be used to cool the crystal rather than the liquid helium used in all prior p-Ge lasers. The open architecture of the permanent magnet facilitates use of cooling fins/heat sinks, which are demonstrated to increase repetition rate and energy output over all prior p-Ge lasers, which do not use such. Since permanent magnets can be cut to any shape and are not restricted to solenoid geometrics, novel laser configurations including ring lasers and oscillator/amplifiers can be realized in contrast to prior p-Ge lasers, which are exclusively oscillators only.