Measurement of small-signal and large-signal responses of packaged laser modules at high temperature

Abstract

In this paper, the pulsed injection method is extended to measure the chip temperature of various packaged laser modules, such as the DFB laser modules, the FP laser modules, and the EML laser modules. An optimal injection condition is obtained by investigating the dependence of the lasing wavelength on the width and period of the injection pulse in a relatively wide temperature range. The small-signal frequency responses and large-signal performances of packaged laser modules at different chip temperature are measured. The adiabatic small-signal modulation characteristics of packaged LD are first extracted. In the large-signal measurement, the effects of chip temperature, bias current and driving signal on the performances of the laser modules are discussed. It has been found that the large-signal performances of the EML modules depend on the different red-shift speeds of the DFB and EAM sections as chip temperature varying, and the optimal characteristics may be achieved at higher temperature.

Dual current injection tunable SBG semiconductor laser with asymmetric π equivalent phase shift

“…As a matter of fact, the two currents injected into the studied laser chip is continuous, the red‐shift of the lasing wavelength caused from the heating effect of the injected currents cannot be ignored [5]. In our experiment, the tunable characteristics of the lasing wavelength depend on the combination of the heating effect and the free carrier plasma effect derived from injected currents.…”

“…As a matter of fact, during the fabrication of a DFB semiconductor laser, the effective refractive index is also difficult to be controlled precisely, so that the lasing wavelength is difficult to be regulated meeting the ITU‐T standard, even if the process for fabricating grating can be precise. There are several methods to tune the lasing wavelength for DFB semiconductor laser, such as changing work temperature [2, 3], varying injection current [4, 5], and multielectrode current injection [6, 7]. Combined precise fabrication and tunable lasing wavelength, a DFB semiconductor laser can meet the ITU‐T standard in WDM system.…”

Single mode operation of a Fabry–Perot laser locked by a tunable laser

“…The laser internal chip temperature can be adjusted using our laser driver and measured using our established method [25]. Figure 5(a) shows the mode shift of the FP-LD with the different chip temperatures.…”