Light frequency synthesizer

A light frequency synthesizer comprising:

• reference light generating means, which generates reference light, the light frequency component of which varies in a stepped manner at specified intervals, repeatedly at pre-specified cycles, and generates a timing signal in accordance with this variance;
• detecting means, which detects a frequency difference between a reference light frequency freely selected from among the light frequency components, and a feedback light frequency of feedback light which is fed back in such a manner as to conform to the reference light frequency, and synchronizes this with the timing signal;
• and
• output light generating means, which generates output light having a light frequency which is controlled in accordance with said frequency difference, and which supplies a portion of said output light to said detecting means as said feedback light.