Electrooptical modulator

Abstract

The invention discloses an electrooptical modulator and relates to the field of laser frequency stabilization. The electrooptical modulator is composed of two titanium phosphate oxygen potassium crystals (2, 5), four electrode plates (1, 3, 4, 6) and an insulating substrate (7). By means of the shape, the structure and the mutual position relation between the two titanium phosphate oxygen potassium crystals (2, 5), light enters in the brewster angle of all light passing end faces of the titanium phosphate oxygen potassium crystals, thus reflection losses are reduced. In addition, reflected light and incident light are obviously separated in space and the etalon effect is prevented from occurring. The two crystals are used in cooperation, and light beams can be transmitted without excursion after passing the modulator. The electrooptical modulator has the advantages that the electrooptical modulator can be used for suppressing high-frequency noise of a laser; when light rays which excurse horizontally enter in the brewster angle, insertion losses of the light rays are small and the etalon effect does not exist.

Description

technical field [0001] The invention relates to the field of laser frequency stabilization and can be applied to the suppression of high-frequency noise of lasers. Background technique [0002] In the field of laser frequency stabilization, piezoelectric ceramics and acousto-optic modulators are often used as frequency correction devices. However, some lasers (such as dye lasers) have high-frequency noise on the order of MHz, and the response bandwidth of piezoelectric ceramics and acousto-optic modulators cannot meet the suppression requirements of high-frequency noise. The response bandwidth of the electro-optic crystal can reach more than MHz, which can be used to control the high-frequency part of the frequency noise. Therefore, inserting the electro-optic crystal modulator in the laser resonator as the actuator of the broadband feedback loop is an effective means to suppress the high-frequency noise of the laser. [0003] Generally speaking, the dielectric propert...

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Problems solved by technology

This solution has two disadvantages: 1. When the crystal is inserted into the cavity, the incident angle of approximately zero degrees will bring a certain reflection loss, which increases the light threshold of the laser; 2. When the light passes through the crystal, it will be inside the crystal many times Reflection, these reflected lights have a good coincidence in space, and mutual interference produces an etalon effect, which is likely to cause instability in the output light mode of the laser

Although coating anti-reflection coatings on the transparent surface of the crystal can greatly reduce the loss and etalon effect, for lasers used in the field of precision measurement today, weak interference can have a huge impact on the performance of the entire laser

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