or I wanna verify if at a further stage in the optical train the conversions are taking place at the "aproximate correct wavelengths" so about 5nm worst case range.
For that kind of resolution I would be looking for a CCD based spectrometer, but 1400nm will be too high, these typically max out around 1100nm (unless ingaas based sensor, but then they start only around 900nm). Thinks of brands like Ocean Optics and Avaspec. These typically work with large diameter fiber inputs, which make is very easy to couple light into it. These are also usb based, light and small, so shipping is not an issue. Prices are around 500€ to 700€. Resolution varies depending on range and slit size (typically between 0.5 and 10nm)
The lasers are not fiber coupled.. i would put a fiber close to the beam and measure scatter from it.. because the power from the lasers would be too much for the sensor.
You will be surprised how difficult it is to get this right with a single mode fiber input. Your signal will be too high or too low. I own an Anritsu MS9710C, and it quite difficult to test anything that is not single mode fiber coupled to start with. There are some free space optic OSA's, but these tend to be even more expensive due to their versatility. As you found out, these can be expensive. I bought mine broken, but still paid around 700€ for it, which was a big gamble.
just peak wavelength by the way!
Then a wavelength meter is the ideal tool. Very high accuracy and high sensitivity. I own an Anritsu MF91A with a 0.6µm to 1µm plug-in. It has about 0.01nm resolution. It was around 200€ on Ebay (which was probably a good deal).
Correct the regular ccd spectrometers don't go higher then 1100 to even 1000nm max.
I really need to reach that 1278nm.
The problem I found with the more common usb spectrometers is that the regular ones go to that 1100nm at best and the deep IR ones go to a minimum of 900nm.,. on top of that the deep IR ones are a rare find.. new 50~60k and never seen them show up on ebay.. so OSA was my second consideration.
The wavelength meter is a GREAT idea! Sadly I haven't been able to find any any on ebay it's still in the thousands.. amazing deal on yours though!
I noticed good deals for OSA's that have "slit errors" which seems like a high price gamble for something that might not be repairable.
Open for wavelength meter suggestions!
Just had a look on Ebay for wavelength meters, it is indeed not a cheap option for the moment also. Mine doesn't cover you range, so it is of no help (doesn't get used here very often, as in the meanwhile I acquired quite a bit of other options...)
About repairing an OSA, it is indeed a big gamble. Mine was quite an easy fix (reseating all connector is I remember correctly), but that is off course no guarantee.
Another option could be a monochromator, on which you install a silicon photodiode or ingaas photodiode, depending of which laser you are testing. I am currently working on one, which I am automating with an arduino cnc shield. I have calibrated it using the spectral line of both a neon bulb and mercury vapor lamp, and achieved a wavelength accuracy of about 0.3nm, and similar resolution. With the installed grating (1200mines/mm 500nm blaze) I can achieve this from +-250nm to 1200nm, but with a different grating it would easily cover your required range (using higher or modes with an optical filter at the input is for high power light sources also an option).
Monochromators are quite affordable on Ebay (200€ to 500€), but are always a project and not ready to use. For computer controlled ready to use versions expect to pay quite a bit more