External cavity broadband tunable laser with double gain mediums of polarization coupling

Abstract

Disclosed is a polarization-coupled dual-laser gain medium external cavity bandwidth tunable laser (400). The laser (400) includes a first laser gain medium (34), a first intracavity collimation lens (38), an active optical phase modulator (41), a tunable acousto-optic filter (26), an intracavity reflector (28), an optics etalon (42) and an intracavity holophote (44) successively installed inside a laser cavity. The laser (400) further includes a second laser gain medium (35), a second intracavity collimation lens (39), a passive polarization rotator (25), an optical polarization combiner (31) installed behind the first intracavity collimation lens (38) and the passive polarization rotator (25), an active polarization rotator (27) installed on the optical path of the output beam of the laser (400), a radio frequency signal source (20), pumping sources for two laser gain media (34, 35), a drive source for the active optical phase modulator (41), a drive source for the active polarization rotator (27), and a laser drive control circuit. The laser (400) has no mechanical movement components and has the features of stable performance, low costs, small size, and easy installation and production, which can meet the requirements of reliable running with a small size in an extreme working environment.

Description

technical field [0001] The invention belongs to the field of optoelectronics, in particular to a polarization-coupled double-gain medium external-cavity broadband tunable laser. Background technique [0002] In the external cavity tunable laser, there are mainly the following tuning technologies: (1) The tuning is carried out by driving the rotation of the grating by a precision stepping motor. The main disadvantages are as follows: First, to achieve precise tuning of optical frequency, The stepping accuracy and repeatability 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 the stepping motor; the third is that the working stability in the harsh working environment is relatively poor, especially The ability to resist various mechanical vibrations is relatively poor. Due to the above-mentioned problems, tunable lasers using this technology are only suitable for use in laborato...

AI Technical Summary

Problems solved by technology

[0002] In the external cavity tunable laser, there are mainly the following tuning technologies: (1) The tuning is carried out by driving the rotation of the grating by a precision stepping motor. The main disadvantages are as follows: First, to achieve precise tuning of optical frequency, The stepping accuracy and repeatability 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 the stepping motor; the third is that the working stability in the harsh working environment is relatively poor, especially The ability to resist various mechanical vibrations is relatively poor. Due to the above-mentioned problems, tunable lasers using this technology are only suitable for use in laboratory working environments.

(2) Use other optical filter devices in gratings or laser resonators, such as optical etalons, to tune the frequency of transmitted light with temperature drift. The advantages of this technology are high tuning accuracy and narrow spectral bandwidth of output light , the disadvantage is that the speed is relatively slow, especially in the case where a wide range of tuning spectrum is required. The range is 400 degrees, therefore, this is difficult to achieve in practical applications

(3) The main disadvantage of MEMS is that it has poor working stability in harsh working environments, especially the poor ability to resist various mechanical vibrations

(4) Using tunable acousto-optic filters for tuning has the advantages of fast tuning speed, no mechanical moving parts, and miniaturization. The disadvantages are that the tuning accuracy is not high and the filtering bandwidth is relatively wide. Therefore, simply using this Technology tunable lasers are only suitable for applications where tuning accuracy and output bandwidth are not high

(5) Using a single laser gain medium, its spectral range is difficult to cover the C spectral band and the L spectral band

[0003] To sum up, the existing technology cannot meet the requirements of various applications of tunable lasers with miniaturization, fast tuning in a wide spectral range, narrow-band laser output and long-term stable operation in harsh environments, especially in optical fiber communications.

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