Frequency of the laser which utilizes the secondary groan signal between laser longitudinal mode and stabilization modulo and stabilization device null

摘要

PURPOSE: To stabilize frequency and output of a laser by using a secondary beat signal between three vertical modes, as an identifying signal for stabilization of a laser frequency or laser output. ;CONSTITUTION: A secondary beat signal detected from a photodetector 2 is converted to a voltage signal, which is proportional to a secondary beat frequency by using a frequency-voltage converter 3. A length of a laser resonator is controlled so as to make a voltage of the voltage signal constant. Light of a laser luminous flux, emitted from a laser 1 which oscillates at three vertical modes, is partially reflected from a luminous flux splitter 4 raised at an angle close to vertical with respect to luminous flux, turned by a mirror 6 after passing through a deflection element 5, injected to the photodetector 2 and subjected to photodetection. Then, a control signal passes through the frequency-voltage converter 3 through a band-pass filter 7 in a frequency band wherein a secondary beat signal can be detected, the length of a resonator is automatically controlled by an automatic servo control device 8 and an output is stabilized simultaneously, together with frequency of the laser.;COPYRIGHT: (C)1993,JPO