Help finding a surface mount transistor

Can anyone help me find this transistor? The code looks like 1Z9D with a dot under the Z. Also looks like an “L” manufacturers mark in front of the number. The part is on an EXFO AXS-100. I have also seen a transistor with the part number 1Z6D in the same place, so I assume they are interchangeable.

Thanks,
Justin

Could that be L1790?