Noise
Problem: General Noise
Common causes:
Suggestions:
Problem: Frequency Dependent Noise
Common causes:
Suggestions:
Common causes:
- Beam blocked
- Low throughput accessory
- Poor environment
- Failing source
- Fogged beamsplitter
- Poorly tuned moving mirror control
- Failing detector
- Electronic fault
Suggestions:
- Follow the infrared beam (conceptually, as it is not visible). Make sure path is unobstructed. Does problem exist with accessories removed?
- Reduce environmental vibrations.
- Inspect beamsplitter for fogging, replace if necessary.
- If poorly controlled moving mirror is suspected, try a different scanning velocity. However, if using a detector that has a considerable frequency response dependence, such as a DTGS detector, results may be ambiguous.
- As last resort, swap detector/electronics/power supplies, one at a time.
Problem: Frequency Dependent Noise
Common causes:
- Noise is greater at higher frequency: interferometer component missaligned
- Misaligned focusing mirror
- Scattering sample
Suggestions:
- Align fixed interferometer mirror or other interferometer component with alignment capability.