low drift low noise current source

[maat]

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.

[zrq]

What's your ECDL's mode-hop free tuning range?
Looking forward to read your paper, especially the part for the diode driver.

[maat]

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.

[Andree Henkel]

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.