High-speed and wide-range continuously tunable method for dfb array

Abstract

The invention provides a method for realizing high-speed and large-range continuous tunability by coordinating single-tube frequency expansion and multi-tube time-sharing switching in a DFB array laser. Extend the optical frequency range of the frequency-sweeping light output through current tuning in a single tube, and realize large wavelength tuning with small-range current tuning, so that the tuning range is not lower than the inherent wavelength interval between adjacent diodes in the DFB array laser. Then different laser diodes in the DFB array are sequentially switched through the control module, thereby realizing high-speed and large-range continuous tunability in the DFB array. Preferably, the cascaded four-wave mixing technology can be used to expand the tuning range of a single laser diode in the DFB array. Compared with the method in the traditional DFB array that achieves wavelength tuning and band coverage through temperature tuning of individual laser diodes, its advantage lies in that wavelength tuning can be achieved completely relying on current without using temperature, so it can achieve high-speed and large-range continuous tunability, and can be quickly locked on a certain wavelength and channel. Moreover, current tuning is beneficial to the closed-loop control of external tuning, such as pre-correction or optical phase-locked loop control methods can be used to linearize the output optical frequency of the laser.

Description

Technical field[0001]The present invention belongs to the field of semiconductor lasers, and more particularly to a method of achieving high-speed high-range continuously tuning in a DFB array laser.Background technique[0002]Distributed Feedback Laser DFB Array Lasers is a very important light source, optical transmission network and optical interconnection, etc., and other WDM large-capacity communication systems, and DFB arrays can overwrite the entire C band through wavelength tuning. Single-chip integrated DFB arrays are generally constructed of a plurality of diode (PDs) having a certain spacing in wavelength and a multimode interference coupler (MMI), and a semiconductor optical amplifier (SOA). The wavelength tuning of different diodes is typically used in modulation mode to cover the entire communication C band. The tuning coefficient of DFB current is small, so the single tube in the DFB array is usually modulated with a small wavelength range by current tuning, not suffici...

AI Technical Summary

Problems solved by technology

Therefore, in the DFB array, only through current tuning between adjacent single diodes, it is not possible to achieve seamless splicing and coverage of the frequency sweep range. In comparison, the DFB temperature tuning coefficient is large, but the temperature tuning can cover adjacent diodes. The wavelength can be spliced ​​without intervals, but the temperature response speed is slow, and the temperature system has a large inertia, which leads to severe oscillations at the target temperature, which is not conducive to closed-loop feedback control to achieve the stability of the tuning process or optical frequency nonlinear correction

This limits its application in specific communication occasions and optical sensing fields (such as optical frequency domain reflection fiber optic link diagnosis and sensing systems, frequency modulation continuous wave ranging systems, etc.)

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