Tunable laser with double output light beams

Abstract

The invention relates to a tunable laser with double output light beams. The first structure of the laser comprises a first laser cavity reflector, a laser gain medium, an intra-cavity collimating lens, an active optical phase modulator, a tunable acoustic-optic filter, a tunable Fabry-Perot filter, a second laser cavity reflector and a laser device controlling and driving system. A zero-level light beam which enters the tunable acoustic-optic filter after being reflected by the first laser cavity reflector forms the first laser output light beam and a zero-level light beam which enters the tunable acoustic-optic filter after being reflected by the second laser cavity reflector forms the second laser output light beam. According to the second structure of the laser, a Fabry-Perot etalon is added in the first structure, so that the purpose of further compressing the laser output frequency bandwidth is achieved. The tunable laser with the double output light beams has the advantages of being reasonable in design, free of mechanical movable part, stable and reliable in performance, low in cost, small in size, easy to install and produce and the like.

Description

technical field [0001] The invention belongs to the field of optoelectronics, in particular to an external cavity-type tunable laser with double output light beams which adopts a tunable Fabry-Perot filter of a liquid crystal optical phase modulator and a tunable acousto-optic filter. Background technique [0002] In external-cavity broadband tunable lasers, the commonly used tuning techniques mainly include the following methods: 1. Tuning is carried out by driving the rotation of the grating through a precision stepping motor. The existing problems are reflected in: First, to achieve precise tuning of optical frequency , the stepping accuracy and repeatability requirements of the stepping motor are very high, so the manufacturing cost is relatively high; the second is that it is not easy to miniaturize due to the use of a stepping motor; the third is that the working stability in harsh working environments is relatively poor, In particular, the ability to resist various me...

AI Technical Summary

Problems solved by technology

[0002]In the external cavity broadband tunable laser, the commonly used tuning techniques mainly include the following methods: 1. The tuning is carried out by driving the rotation of the grating by a precision stepping motor, and the The existing problems are reflected in: First, in order to realize the precise tuning of optical frequency, the stepping accuracy and repeatability of the stepping motor are required to be very high, so the manufacturing cost is relatively high; second, due to the use of stepping motors, it is not easy to achieve miniaturization ; The third is that the working stability in harsh working environments is relatively poor, especially the ability to resist various mechanical vibrations is relatively poor. Therefore, tunable lasers using this technology are only suitable for use in laboratory working environments

2. Using tunable acousto-optic filters for tuning has the advantages of fast tuning speed, no mechanical moving parts, and can be miniaturized. The disadvantage is that the filter bandwidth of tunable acousto-optic filters is relatively wide, which makes the tuning accuracy of the laser lower. High, therefore, it is difficult to achieve precise continuous tunability of tunable lasers using this technology alone, and it is only suitable for applications that do not require high tuning accuracy and output bandwidth

3. Use gratings or other optical filter devices in the laser resonator, such as optical etalons, to tune the frequency of transmitted light with temperature drift. The advantages are high tuning accuracy and narrow spectral bandwidth of the output light. The disadvantage is that the speed is relatively high. Slow, especially in the case where a wide tuning spectrum range is required, this shortcoming is particularly obvious, for example: the temperature drift coefficient of the optical filter device is 0.02 nanometers / degree, the required optical spectrum range is 20 nanometers, and the temperature adjustment range is 100 degrees, This is difficult to achieve in practical applications

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