Dear there,
Our project needs to drive a Semiconductor Optical Amplifier (SOA) to generate a 20ns width and 2ns rise time optical pulse. The peak drive current is ~600mA. The LMH6525’s parameters are good for the application for its fast rise time and the high peak current.
The question relates to the on/off extinction ratio (ER) of the optical pulse. The SOA allows generating an optical pulse with ER more than 80dB. When there is any current goes through the SOA, it starts to work and gives optical power output. The LMH6525 has four individual “Enable” PINs for each of the current channel. And it has a group “Enable” PIN for all four channels as well. When there are two lasers on the board, the group Enable PIN could select which one to drive. In our case, we have only one laser. Therefore, we use the group Enable PIN as a switch to set the laser on and off state.
In our application, we propose to leave the individual PINs always “on” and use the group “Enable” PIN to control the laser “on/off”. when the laser is in “Off” state, is there any leakage current that still goes to the laser? Although The leakage current might only generate very weak optical power, it does affect the optical pulse “on/off” ER. If it has, what is the level of the leakage current?
Thank you.
