Hello, Is there a way I can operate QL94R6SA-S (940 nm) laser diode at 935 nm? What would be the working conditions?
Thank you!
Hello rayan.wehbe and welcome to the DigiKey TechForum.
According to the datasheet for QL94R6SA-S the minimum wavelength would be 930nm with 940nm being the typical. So, it may be possible that it is already closer to the 935nm wavelength.
Unfortunately, I wouldn’t be able to suggest anyway that you could potentially use this outside the specifications listed on the manufacutrers documentation.
Hi rayan.wehbe,
Based on those specifications, the wavelength could be anywhere between 930nm and 955nm when driven at Po=300mW and maintained at a case temperature of 25°C. We have no way to know where any individual part would fall within this range.
If you are interested in trying to adjust the wavelength while in use, there are a few things one might do.
First, one can adjust drive current. As a general rule, the output wavelength tends to shift to a shorter wavelength as drive current is reduced.
Second, one can try to adjust the case temperature of the laser diode (this can of course be very challenging). However, if one can manage to reduce the case temperature, the output will tend to shift to a shorter wavelength. As an example, I found this chart within the datasheet of the Rohm RLD94PZJ5-00A 940nm laser diode.
Wavelength shift of Rohm RLD94PZJ5-00A with shift in case temperature
Thank you very much for your helpful response.
Is there a way I can get a similar graph for the laser diode by QSI laser, QL94R6SA-S? Or maybe the wavelength’s temperature dependency/ sensitivity ?
Thank you
Best,
Rayan Wehbe
TAMOS Inc.
Houston, Texas
Hi rayan.wehbe,
I’d say that is pretty unlikely, as they don’t seem to post such information anywhere on their website. However, one could inquire directly with the manufacturer, just to see.