I'm currently working on a project to switch a semiconductor optical amplifier (SOA) on and off very quickly. The rise and fall times need to be very short - under a nanosecond. The SOA also needs to have the capability to be kept on indefinitely - the bandwidth required would need to include DC.
SOAs behave broadly like laser diodes, since they are essentially laser diodes without a cavity. As such, I have been trying to find a suitable laser diode driver.
Most of the drivers I have found so far have required AC coupling on the input and output, which renders DC coupling impossible. However, the ONET4211LD laser diode driver seems broadly suitable - it allows for DC coupling on the input.
Unfortunately, I noticed that a lower bitrate limit of 155 Mbps is listed in the title and summary, implying that there is a lower limit on the bandwidth, and therefore that the driver cannot output a constant modulation current. Is this the case? There is no mention of bandwidth elsewhere in the datasheet (as far as I can tell).