Optical Frequency Precisely Tunable Lasers

Abstract

The invention relates to a precision optical frequency tunable laser. The laser includes: a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter and an intracavity total reflection mirror all arranged sequentially in a laser cavity, and the tunable laser further includes an active polarization rotator, a polarization beam splitter, two etalons, a temperature control system attached to the etalons, two total reflection mirrors, a radio frequency signal source, a laser pumping source, an active optical phase modulator drive source, an active polarization rotator drive source and a laser drive control circuit. Through the temperature control system attached to the etalons, stable laser output and the precision optical frequency tuning less than 1 GHz within a wide spectrum range can be realized, thereby greatly reducing the bandwidth requirements in achieving narrowband filtering for the tunable acousto-optic filter. The invention is compact with high performance, low cost for volume production and installation, and achieves stable tunable laser output within a wide spectrum range.

Description

technical field [0001] The invention belongs to the field of optoelectronics, in particular to an optical frequency precision tunable laser. Background technique [0002] In external cavity tunable lasers, there are usually the following three tuning techniques. The first tuning technology is to tune by the rotation of the grating driven by the precision stepping motor. The main disadvantages of this technology are as follows: First, in order to realize the precise tuning of the optical frequency, the stepping accuracy of the stepping motor The requirement of repeatability and repeatability is very high, so the manufacturing cost is relatively high; the second is that it is not easy to miniaturize due to the use of stepping motors; the third is that the working stability in harsh working environments is relatively poor, especially the ability to resist various mechanical vibrations Relatively poor. Due to the above-mentioned problems, the tunable laser using this technolog...

AI Technical Summary

Problems solved by technology

The first tuning technology is to tune by the rotation of the grating driven by the precision stepping motor. The main disadvantages of this technology are as follows: First, in order to realize the precise tuning of the optical frequency, the stepping accuracy of the stepping motor The requirement of repeatability and repeatability is very high, so the manufacturing cost is relatively high; the second is that it is not easy to miniaturize due to the use of stepping motors; the third is that the working stability in harsh working environments is relatively poor, especially the ability to resist various mechanical vibrations Relatively poor

Due to the above-mentioned problems, the tunable laser using this technology is only suitable for use in the laboratory working environment

The second tuning technology is to use a tunable acousto-optic filter for tuning. The advantages of this technology are fast tuning speed, no mechanical moving parts, and miniaturization. The disadvantage is that the tuning accuracy is not high and the filtering bandwidth is relatively wide. Therefore, , the tunable laser using this technology alone is only suitable for applications where the tuning accuracy and output bandwidth are not high

The third tuning technology is to use other optical filter devices in the grating or laser resonator, such as optical etalons, to tune the frequency of transmitted light with temperature drift. The advantages of this tuning technology are high tuning accuracy and output light. The spectral bandwidth is relatively narrow, and the disadvantage is that the speed is relatively slow, especially when the tuning spectral range is required to be wide. 20 nanometers, the temperature adjustment range is 100 degrees, which is difficult to achieve in practical applications

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