Which company produces IR Sensor in the range of 2-4 micrometer wavelength?

Hi Everyone.

We're planning to study the IR absorption on various fluids. What we know so far is that the IR length which is absorbed by these fluids is in the range of 2-4 micrometre.

I searched everywhere over internet but couldn't find any transmitter/receiver in that range.

Could you please let me know which company manufactures IR sensors in the range of 2-4 micrometres?

Thanks in advance 

When you say 2-4, do you mean that you need to span the whole range, or you are looking for one wavelength within the range.
If it is the latter, then there are LEDs that will do as a source, if the former, then you are looking at a more specialized device.
As far as detectors go, you have more options.
I would suggest you look at companies that specialize in photonic applications as their core business.
See link below
http://www.photonics.com/Category.aspx?CatID=21250
Two that I have used in the past are Hamamatsu and Thor Labs, their web sites are below. The parts don't come cheap, however.
http://www.hamamatsu.com/us/en/index.html
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=2814
Hamamatsu have interesting app notes, I have included a link to one below,
https://www.hamamatsu.com/resources/pdf/ssd/infrared_kird9001e.pdf
Otherwise, you will need to look at general purpose IR devices, by going through data sheets you may find something.
This link shows some of the IR LED manufacturers,
http://www.directindustry.com/industrial-manufacturer/infrared-led-78089.html
There is a slight spread in the spectral characteristics of LEDs, with optical filtering you could possibly select the wavelength you need. LED IR detectors are easier to find, just search for IR photodetectors on the web.
The spectral spread for IR detectors is usually quite broad, and many operate into the IR with good sensitivity, it is just a case of looking at data sheets.

Cheers,
Richard

Thanks Richard,

We are looking for a CW laser diode at any wavelength between 2.6 to 3.6um and max 10mW power. Our maximum budget for this part only is £800. Thorlab offer was about £3000. And Hamamatsu does not cover that wavelength. Any ideas?

Best regards,
Amir

No, at these wavelengths you are talking about specialist products, which are not manufactured in large quantities, and are often at the cutting edge of the technology, so they are going to be expensive. We used to use a broadband light source and a monochromator in the IR region, at the time there were no laser diodes that worked in the region, and we needed a tunable source anyway.
Sorry I can't be of any help,
cheers,
Richard