Wavelength Tunable External Cavity Lasers

Abstract

A wavelength tunable external-cavity laser. Same comprises a resonant cavity consisting of a phase compensator (3), a tunable grid filter (4), a broadband tunable filter (5), a first coupling lens (6), and a gain component (7), an isolator (9), a second coupling lens (10), and an optical fiber (11). The wavelength tunable external-cavity laser may also comprise a photodetector (1), a third coupling lens (8), and a combined filter-reflector (2) in the resonant cavity. The broadband tunable filter can be manufactured by employing a liquid crystal etalon or be manufactured by combining a micro-mechanical rotating mirror and a grating. The solution allows for greatly reduced difficulty in manufacturing the broadband tunable filter, thus reducing component manufacturing costs, allows for easy implementation of a tunable laser of 50 GHz or lower frequency intervals, and also allows for free wavelength tuning of the grating via a certain control method.

Description

technical field [0001] The invention relates to the technical field of lasers, in particular to a wavelength-tunable external-cavity laser with adjustable wavelength and arbitrarily variable wavelength intervals. The laser is applicable to optical communication networks with adjustable wavelengths. Background technique [0002] Traditional optical communication networks mainly use fixed-wavelength lasers, but with the increase in the number of channels, the use of fixed-wavelength lasers makes network maintenance and device backup more difficult and costly. For next-generation optical communication networks, tunable lasers are key devices for realizing intelligent optical networks, which can provide greater flexibility, faster speed, and ultimately lower costs for system maintenance and wavelength deployment. Existing DWDM (Dense Wavelength Division Multiplexing) systems are generally 50GHz frequency or 100GHz frequency interval systems. In order to better utilize the spectr...

AI Technical Summary

Problems solved by technology

By precisely controlling the peak wavelength of the transmission peak of the etalon by temperature, the wavelength can be tuned arbitrarily in theory. This method has a simple structure, but the temperature control method is very complicated.

U.S. Patent US7991024B2 discloses a liquid crystal type tunable external cavity laser, which uses a liquid crystal etalon as a channel selection element, and a fixed etalon to generate a fixed frequency grid. This structure has a small frequency grid interval. The bandwidth and stability of the liquid crystal etalon are very high. Due to the material properties and manufacturing process characteristics of the liquid crystal etalon, it is very difficult to realize a liquid crystal etalon with a very narrow bandwidth. Therefore, for lasers with a frequency interval of 50 GHz or lower, The above structure is actually difficult to realize

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