Hello,
I am trying to modulate at least a 1 Mhz digital signal into the laser beam of the 50 mW 405 nm laser diode SLD3232VF. The signal comes from MCU @ 3.3V logic level - however it can be shifted as needed.
I started with the simplest setup - LM317 with BC337 transistor which can pull the adjust pin of the regulator low (which shuts down the laser) or can act as a switch (I tried both variants). After some troubles with the saturiation of the transistor I managed to switch the the transistor at 1 Mhz. In this setup with connected resistor instead of the laser, I could saw a nice 1 Mhz rectangle signal in the current on the oscilloscope. However when I switched back to laser, everything works up 500 kHz - than the laser beam dissapears. However the scope shows nice rectangle signal at the laser input..
My question is - how to switch laser on these (even better higher - I am aiming for 4-5 Mhz) frequencies? What am I doing wrong with my setup? How could it be improved? How could it be implemented in another way?
Is there a complete driver module, which operate on these frequencies (at reasonable price)?
PS: I'd like to also switch to 500 mW in the future instead of 50 mW.
I am trying to modulate at least a 1 Mhz digital signal into the laser beam of the 50 mW 405 nm laser diode SLD3232VF. The signal comes from MCU @ 3.3V logic level - however it can be shifted as needed.
I started with the simplest setup - LM317 with BC337 transistor which can pull the adjust pin of the regulator low (which shuts down the laser) or can act as a switch (I tried both variants). After some troubles with the saturiation of the transistor I managed to switch the the transistor at 1 Mhz. In this setup with connected resistor instead of the laser, I could saw a nice 1 Mhz rectangle signal in the current on the oscilloscope. However when I switched back to laser, everything works up 500 kHz - than the laser beam dissapears. However the scope shows nice rectangle signal at the laser input..
My question is - how to switch laser on these (even better higher - I am aiming for 4-5 Mhz) frequencies? What am I doing wrong with my setup? How could it be improved? How could it be implemented in another way?
Is there a complete driver module, which operate on these frequencies (at reasonable price)?
PS: I'd like to also switch to 500 mW in the future instead of 50 mW.
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