a camera which records images at different wavelengths using optical filters
You use a black/white sensor that has no RGB filters.
Then, you put your IR filter in front of the camera.  Now you have a camera that sees infrared only.

Most CMOS camera elements are IR sensitive and have an extra filter to remove IR so as not to make a mess when using RGB.

You can get black and white CMOS cameras commercially, some even have built in IR LEDs that can be used to "light up" the view field with IR.

Take a look around.  You may even find a commercial unit with the correct IR filter already built in.