JPS62125220U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention;
This figure is a block diagram of the PLL circuit, FIG. 3 is a block diagram showing another embodiment of the present invention, and FIG. 4 is a block diagram showing a conventional example. 1, 31... Laser, 6, 14, 34, 35... Acousto-optic element, 19, 49... Outgoing light beam, 20,
40... Drive circuit, 21, 41... Crystal oscillator, 22
A, 22B, 42A, 42B...PLL circuit, 10
1... Phase comparator, 102... Low pass filter, 1
03... Voltage controlled oscillator, 104... Frequency divider.

Claims (1)

[Scope of utility model registration request] In an optical frequency shifter that separates a laser beam into two optical beams and shifts the frequency of each optical beam using an acousto-optic element, the optical frequency shifter emits two linearly polarized lights with different optical frequencies onto the same optical path. an oscillator, a phase comparator whose first input is the output of this reference crystal oscillator, and the output of this phase comparator is input as a control signal through a low-pass filter, and in a steady state, the frequency of the first input and the frequency of the first input as described below. A voltage controlled oscillator whose output is the product of the frequency division ratio of the frequency divider, and a frequency divider which divides the output of the voltage controlled oscillator and outputs the frequency as the second input of the phase comparator. An optical frequency shifter characterized in that the acousto-optic element is driven by an output signal of a controlled oscillator.