Highly stable high frequency standard - varies hyperfine structure frequency with different light intensities causing regulation of laser light frequency

摘要

The standard has a resonance cell (1) in a hollow resonator (2). A frequency modulated microwave oscillator (3,4,5) stimulates the resonator. A laser light source (6) provides pumping light. A regulator circuit regulates the oscillator frequency. This circuit has a photocell (11) which receives the laser beam emitted through the resonance cell and a phase responsive rectifier (13) is timed to the oscillator modulation frequency. Laser light passes through the cell with different intensities. The frequency of the hyperfine structure characteristic is varied through the different intensities and the frequency of the laser light source is adjusted to minimise the light shift effect. ADVANTAGE - Continually keeps light shift effect at minimum.