Electro-optical modulator

Abstract

The invention provides an electro-optic modulator, which is composed of a semi-conductor laser (1), an optic fiber (2), a collimator (3), a polarizer (4), an electro-optic modulating crystal unit (5), a polarization analyzer (6), a laser power supply (9), a power supply (10), a light receiver (7), a light receiver (8), a driver (11) and a coding signal source (12). All portions are photoelectrically coupled via fibers, the collimator (3) uses a self-focus lens, and the electro-optic modulating crystal unit (5) uses combination modulation method and uses wideband travelling wave electrodes. The electric-optic modulator can realize 810nm laser modulation of 100-500mW output laser power and 0.5-5.0GHz modulation bandwidth, to resolve the limitation between power and bandwidth of electro-optic modulator. The invention can improve the output laser power of electro-optic modulator via reducing bandwidth some, to meet the demands of free space and near space laser communication.

Description

technical field [0001] The invention belongs to the technical field of space laser communication and relates to an electro-optic modulator. Background technique [0002] In the space laser communication system, the communication laser needs to be modulated, and the electro-optic modulator is a device that uses the electro-optic effect of the electro-optic modulation crystal to realize the modulation of the laser. A 40GHz composite electrode type high-speed electro-optic modulator was introduced in the "40GHz Lithium Niobate Electro-optic Modulator" document in the 11th issue of 2001 of "Optoelectronics·Laser". A 100GHz high-speed waveguide electro-optic modulator was introduced in the "100GHz Composite Traveling Wave Electrode Lithium Niobate Electro-optic Modulator" published in "Acta Photonica Sinica" in 2002, Volume 31, Issue OZ2. The research method and development trend of high-speed electro-optic modulators are introduced in the "Progress of High-speed Polymer Electro...

AI Technical Summary

Problems solved by technology

Due to the attenuation characteristics of laser in atmospheric transmission, the laser wavelength is preferably 810nm, and the power and bandwidth of the electro-optic modulator are mutually restricted. Although the electro-optic modulator introduced in the above literature has a high bandwidth, the output laser power is less than 10mW, and the modulated laser wavelength is not For the 810nm series, it is not suitable for long-distance free space and near-space laser communication for laser wavelength and power requirements

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