CW DUV Laser With Improved Stability

摘要

A deep ultra-violet (DUV) continuous wave (CW) laser includes a fundamental CW laser configured to generate a fundamental frequency with a corresponding wavelength between about 1 μm and 1.1 μm, a third harmonic generator module including one or more non-linear optical (NLO) crystals that generate a third harmonic and an optional second harmonic, and a fifth harmonic generator. The fifth harmonic generator module includes a cavity resonant at the fundamental frequency, and combines the fundamental frequency with the third harmonic in a first NLO crystal to generate a fourth harmonic, then combines the fourth harmonic with unconsumed fundamental frequency in a second NLO crystal to generate the fifth harmonic. One or more lenses are used to focus the third and fourth harmonics in the first and second NLO crystals, respectively.

主权项

1. A deep ultra-violet (DUV) continuous wave (CW) laser comprising:
a fundamental CW laser configured to generate a fundamental frequency with a corresponding wavelength between about 1 μm and 1.1 μm; a third harmonic generator module configured to generate a third harmonic using a first portion of the fundamental frequency; a fifth harmonic generator module comprising:
a plurality of optical elements forming a cavity resonant at the corresponding wavelength of the fundamental frequency, the plurality of optical elements being configured to operably couple the third harmonic and a second portion of the fundamental frequency in the cavity, andfirst and second NLO crystals operably disposed in the cavity and collectively configured to generate a fifth harmonic by combining the second fundamental frequency portion and the third harmonic.