Sub-microsecond wavelength stabilization of tunable lasers with the internal wavelength locker

Abstract

We proposed a method of accelerating the wavelength stabilization after wavelength switching of the tunable distributed amplification-distributed feedback (TDA-DFB) laser using the internal wavelength locker to reduce the size and the cost of the wavelength control system. The configuration of the wavelength stabilization system based on this locker was as follows. At the wavelength locker, the light intensity after an optical filter is detected as a current by the photodiodes (PDs). Then, for estimating the wavelength, the current is processed by the current/voltage-converting circuit (IVC), logarithm amplifier (Log Amp) and field programmable gate array (FPGA). Finally, the laser current is tuned to the desired wavelength with reference to the estimated wavelength. With this control system the wavelength is stabilized within 800 ns after wavelength switching, which is even faster than that with the conventional control system.

High-speed and long-term wavelength stabilization of tunable distributed amplification distributed feedback laser after laser activation with feedforward and feedback control

“…[27][28][29][30][31][32][33] In addition, by adapting feedback control technology, long-term thermal drift is canceled and long-term wavelength stabilization was realized. [33][34][35] Our proposed current control technique enabled us to switch the wavelength of a single TDA-DFB laser in a range of 6 nm.…”