Semiconductor laser component element, optical fiber amplifier and photo communication system using said component element

Abstract

Disclosed is a semiconductor laser module which is advantageous as a pumping source for Raman amplification because of its high optical output and excellent wavelength stability. The module comprises a Fabry-Pérot semiconductor laser device to which a fiber Bragg grating having a wavelength selectivity and showing a specific reflectivity with respect to a specific wavelength is optically coupled, wherein given that a cavity length of the semiconductor laser device is L ( mu m), a reflection bandwidth of the fiber Bragg grating is DELTA lambda (nm) and a reflectivity of said front facet is R1 (%) and a peak reflectivity of said optical feedback part is R2 (%), following equations are satisfied among L, R1 and R2 1000 mu m ≤ L ≤ 3500 mu m, 0.01% ≤ R1 + c<2>R2 ≤ 4% and R1 / R2 ≤ 0.8 where c represents a coupling efficiency between the semiconductor laser device and the fiber Bragg grating. It is preferable that 0.2 nm ≤ DELTA lambda ≤ 3 nm should be satisfied. <IMAGE>

Description

technical field [0001] The invention relates to a semiconductor laser assembly designed as an excitation light source of an optical communication system. In more detail, it involves a Fabry-Perot type semiconductor laser element and a fiber Bragg grating (Fiber Brag Grating, FBG), a dielectric multilayer filter, a distributed Bragg reflector (DBR ) and other optical feedback components to form a composite resonator type semiconductor laser component, which can be used as a laser component that has the characteristics of oscillating a high-output excitation laser, has good optical stability and has the ability to oscillate an excitation laser It is a laser component with unique characteristics and can suppress distortion, for example, it is suitable for the excitation light source used in the wavelength division multiplexing communication method of the Raman amplification method. Background technique [0002] As an optical communication system for transmitting a plurality of...

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Problems solved by technology

[0020] (2) When the central wavelength of the excitation laser light from the laser unit fluctuates, the wavelength band of the Raman gain also fluctuates in response to the fluctuation, and a mismatch occurs between the wavelengths of the signal light to be optically amplified, which is very difficult. Difficult to perform purposed light amplification

[0022] (3) In the Raman amplification method, when there is a fluctuation (swing) in the intensity of the excitation laser light, the Raman gain swings and it makes the signal-to-noise ratio (S / N ratio, signal-to-noise ratio) of the signal light decrease

Furthermore, when multiplexing is performed with a wavelength combining coupler, the multiplexing loss increases

Conversely, when the oscillation spectrum width is too narrow, it is difficult to reduce the polarization dependence of Raman gain, and the current-light output characteristics of the laser component will be distorted, and the light output from the laser component will be limited

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