Features of Interferometers
Observation of dynamic phenomena of 1µm or less that are unrecognizable by human senses often uses interferometers.
For example, all the basic principles such as surface accuracy measurement of optics, an end measuring machine used for precise measurement of distance or travel, equipment capable of measuring fast and minute changes such as speedometer or vibrometer utilize interference of light.
- Resolution of 1µm or less
- Non-contact (non-destructive) measurement
- Wide range (two-dimensional) measurement
- Surface accuracy measurement
- End measuring machine
- Speedometer, vibrometer
An interferometer provides high resolution, but the range that an optical system can measure is not so broad.
This is because the periodicity of waves makes identification of a phase difference of an integral multiple of waves difficult.
Most of the commercially available interferometry devices consist of an optical system of interferometer and an analysis device for interference signals.
Advanced electronics used in the analysis device enable measurement both with high resolution and broad measurement range.
This chapter introduces interferometers consisting of only an optical system, not fitted with an analysis device for interference signals.
The range available for observation is therefore very limited.
However these interferometers are sufficient for the purpose of basic interferometry experiments or theory testing.
Interference is utilized for practical purposes in many fields.
These fields can use the interferometers as basic experiment devices.
- Heterodyne interference
- Laser gyro
- Optical Coherence Tomography (OCT)
- Time-resolved interferometry