Fast wavelength switching with tunable distributed amplification distributed feedback laser by feedforward control technique

Abstract

We proposed a method of accelerating the wavelength switching of a tunable distributed amplification distributed feedback (DFB) laser by feedforward control. From experimental laser responses, we designed and simulated feedforward controllers using MATLAB/Simulink so as to reduce the time for wavelength stabilization. We applied this method to two different cases involving a laser drive circuit with a large output current and a 50 ns rise time, and a laser drive circuit with a moderate output current and a 5 ns rise time. In both cases, we showed that the wavelength switching times were improved from 450 to 150 ns and from 75 to 35 ns, respectively. From these results, the proposed control technique is confirmed to be efficient for possible practical applications.

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

“…From these results, we confirm that the proposed wavelength control system is effective in fast wavelength stabilization of the TDA-DFB laser and the switching time is shorter than that in our previous control system with external equipment such as the MZI and high-speed PDs. In the future, by combining feedforward and feedback control, the effectiveness of which we have already confirmed and with which we achieved 320 ns wavelength switching with the external locker, [31][32][33][34] the switching time will be improved to be less than 300 ns with the internal wavelength locker.…”

Strategy of full-C-band fast wavelength switching and aging mitigation at tunable DFB laser array with current/temperature cooperative control

“…Besides, the switching time can be further reduced by the feedforward control with an appropriately designed injection current waveform instead of the stepwise injection current waveform used in this experiment. 30) Next, for switching wider than 400 GHz, switching between two lasers was conducted. We applied the cooperative control at switching from LD12 to LD1, shown in Fig.…”

Full‐range wavelength switching at tunable distributed amplification‐DFB laser with high‐accuracy feedforward control

“…Our previous linear model [4], based on the transfer function in the frequency domain, was not effective enough for wide‐range wavelength switching due to non‐linearity. Thus, we developed a more accurate laser model, which is as follows: …”

“…As a high‐speed wavelength stabilisation technique, we previously proposed the feedforward (FF) control method to compensate for the thermal drift by designing a proper current waveform. By applying the FF control designed with the linear model to 200‐GHz‐wide wavelength switching, a wavelength switching time of 35 ns was achieved [4]. In addition, aiming for widening the wavelength switching range, we developed the higher‐accuracy control model accounting for the laser non‐linearity and reduced the control error, compared with our previous linear model.…”