Laser light intensity stabilization system using acousto-optic elements

Abstract

Abstract PURPOSE:To stabilize the quantity of laser light, by inputting plural ultrasonic waves through a piezoelectric oscillator to an acousto-optic element, reflecting partly the exit light except the diffracted light of the 1st frequency with a semitransparent mirror, converting the same to the signal to be controlled, controlling the signal with the 1st frequency component and using the other frequency component as an optional modulating signal. CONSTITUTION:When the light from a laser light source 1 is made incident to an acousto-optic element 2 and an electrical signal of a certain frequency is made incident to a piezoelectric oscillator 2l, the signal is converted to an ultrasonic wave which advances through 2a and generates diffracted light I1, I2. The diffracted light are reflected by a mirror 3a and are conducted to a photodetector 4. The resulted signal is compared with a reference voltage V1 in a comparator 5, and the difference thereof is fed to a modulator 6 which modulates the amplitude of the signal of the oscillator 7. The modulated signal is applied through an intermediate amplifier 8, a mixer 9 and an amplifier 10 to the element 2, by which the exit light I2 is modulated according to the signal V2. Since the sum of the exit light I0 and I2 is made constant, the exit light I2 accomplishes stable modulation operation without receiving the influence of the fluctuation in the incident light I even if said fluctuation arises.

Inventors

• 👤 Fumio Tanaka
• 👤 文雄 田中

Bibliographic Details