Q-modulation semiconductor laser with electric absorption grating structure

A grating structure and laser technology, applied in semiconductor lasers, lasers, laser parts, etc., can solve the problems of high cost, complex production, and difficult to integrate, and achieve the effect of high extinction ratio, high speed, and improved modulation speed.

CN1851990AInactive Publication Date: 2006-10-25何建军
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2006-10-25
Estimated Expiration
Not applicable · inactive patent

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Abstract

This invention discloses a Q-modulated semiconductor laser with an electric absorption structure including a distributed feed-back grating of lambda / 4 phase shift, two separated upper electrodes depositing on the top of the grating, an electrode depositing on the base of the laser as the public base, in which, the first upper electrode covers part of the grating including a phase shift region providing gain to the laser by injecting constant current, a second upper electrode covers the rest part of the grating away from the phase shift region as the Q-modulator of the laser and electric signals can be added to the second upper electrode to change the absorption coefficient of the waveguide of the modulator region and alter the Q value of the laser so as to alter the laser threshold value and output power.
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Description

technical field

[0001] The present invention relates to semiconductor lasers and modulators, and more particularly to a quarter-wavelength phase-shifted distributed feedback laser or distributed Bragg reflection monolithically integrated with a Q-modulator that utilizes current injection or electroabsorption effects to vary the quality factor of the laser laser. Background technique

[0002] High-speed semiconductor lasers and modulators are key components of today's fiber optic communication systems. The rapid increase in Internet traffic requires these optics to handle ever greater bit rates. It is the simplest method to directly modulate the optical signal intensity by changing the bias current of the laser, and it does not require an external modulator. However, a directly modulated laser has fundamental speed limitations and also exhibits transient oscillations with a frequency equal to its relaxation oscillation frequency. Wavelength chirp is another problem with di...

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Embodiment Construction

[0031] The present invention will be described in detail below according to the drawings and embodiments.

[0032] The Q-modulated semiconductor laser of the present invention has many different specific structures, wherein the laser resonator can be based on a distributed feedback (DFB) grating or a distributed Bragg reflection (DBR) grating with a phase shift, respectively.

[0033] The Q factor or quality factor of a laser resonator is used to measure how much light from the laser gain medium is fed back through the optical resonator. A high Q factor means that the light travels in the resonator and suffers less loss every time it goes back and forth. . The principle of Q-modulation is to use a device that can change the Q factor of the resonator to change the laser output optical power, which has been applied in Q-switched dye or solid-state lasers that generate periodic short pulses. Common prior art methods for implementing Q-switching include using rotating mirrors in ...