The singlemode 0.1 pm target is easy to hit. I will look up the numbers on our ECDLs to give you a ballpark figure
That would be very much appreciated.
ECDL: external cavity diode laser?
ECDL = external cavity diode laser
Regarding the linewidth, we typically use a self-heterodyne beat. So we split the beam and sent one side down a 25 km fiber, then superimpose the beams again. That way, we measured our 960 nm lasers to have a free-running linewidth of 25 kHz @ tau = 120 µs limited by mechanical resonances. The external resonator is a 60 mm aluminum block. Send me PM if you want to know more (publication is pending). The 25 kHz is what you get with a very good diode driver (in-house dev., publication pending) and it is not limited by the driver, but rather the environment. Spoiler: Toptica is way above 100 kHz (depending on the generation of laser and driver of course), but your target is closer to several MHz, so don't sweat it.
Edit: I just remembered, that the LT1128 is using a bias current cancelling circuit. So try to match the source resistance when working with an input impedance of more than 1k. See p. 6 of the LT1128 datasheet.
What's your ECDL's mode-hop free tuning range?
Looking forward to read your paper, especially the part for the diode driver.
What's your ECDL's mode-hop free tuning range?
Looking forward to read your paper, especially the part for the diode driver.
Typical values for our 780 nm diodes is something like 1 Ghz. Example diodes are Sharp GH0782RA2C or Thorlabs L785H1. Some individual lasers are better than that and may have up to 2 GHz. AR-coated diodes (of which we only use a few) can do something like 10 Ghz. Blue laser diodes are a lot more finicky and typically have about 500 MHz or less.
Our Application is more focused on stability. Therefore we use filter based lasers and no gratings.
Looking forward to learn about the current source part too.
My Driver is intended to drive a 405nm diode, tuning is not intended. Just trimming temperature and current in combination to get mode hop free operation at desired power.