on the datasheet, it says the Operating Current is 20-29mA, and Forward Voltage is 1.2-1.5V.
But when I test on the circuit, when the Operating Current is between that range, the Forward Voltage is below 1.2V. When the Forward Voltage is between the range, the Operating Current is too high (~40-50mA).
This is the Laser Driver circuit I designed:
during the test, there is some voltage drop on the BJT.
The question is, I'm afraid the current through diode is too high and will damage the diode. But when the current is between the normal range, the laser diode spectrum is not perfect (linewidth is not narrow enough). Can anyone tell me how to solve this? Thanks!
But when I test on the circuit, when the Operating Current is between that range, the Forward Voltage is below 1.2V. When the Forward Voltage is between the range, the Operating Current is too high (~40-50mA).
This is the Laser Driver circuit I designed:
during the test, there is some voltage drop on the BJT.
The question is, I'm afraid the current through diode is too high and will damage the diode. But when the current is between the normal range, the laser diode spectrum is not perfect (linewidth is not narrow enough). Can anyone tell me how to solve this? Thanks!