Efficient Single-Frequency Light Sources with Emission Wavelengths from the Visible to the Infrared Spectral Region

Abstract

For laser-based metrology, efficient sources of stable coherent radiation in the visible and near infrared spectral region are required. While stablity is a common request of most metrology applications, the desired laser wavelength differs with the specific application. Fiber sensors require laser emission at their attenuation minimums at 1.3µm and 1.5µm [1], whereas visible light sources are advantageous when the signal strength increases with the laser frequency, for example in laser-Doppler-velocimetry [2]. A further advantage of visible light is the easy optical alignment. Diode-pumped solid-state lasers are attractive sources for metrology applications because of their high inherent intensity and frequency stability. However, the emission of most solid-state lasers is limited to the near infrared spectral region. We report on stable single-frequency light sources with emission wavelength covering the spectral range from visible to near infrared.