Fiber Michelson or Mach-Zehnder Interferometer
A Michelson or Mach-Zehnder interferometer is capable of converting relative phase variations between two optical beams split from a single light source into intensity variations at the output of the interferometer. This capability allows us to provide fiber-based, low-noise, Michelson or Mach-Zehnder interferometers as an optical phase discriminator, which is very useful for many fiber optical applications, such as phase noise characterization of highly-coherent lasers, phase demodulation of fiber laser sensor array, and fiber Bragg grating sensor interrogation.
An environmentally-insensitive fiber Michelson or Mach-Zehnder interferometer can be used for phase noise (or frequency noise) characterization of single-frequency lasers (such as DFB diode lasers, external cavity diode lasers, and DFB fiber lasers). Polarization fading can be eliminated by using either a polarization-maintaining fiber interferometer (either Michelson or Mach-Zehnder) or a non-polarization-maintaining fiber Michelson interferometer in combination with phase conjugate mirrors (i.e., Faraday rotator mirrors). In such an interferometer, the unbalanced fiber length (or optical path difference) between two interferometer arms defines its free-spectral range (FSR), determining the resolution of laser phase noise or frequency noise characterization.
An environmentally-insensitive fiber Michelson or Mach-Zehnder interferometer can also be used for fiber sensor interrogation, including fiber laser sensors and fiber Bragg grating (FBG) sensors. One arm of such a fiber interferometer can be piezo-electrically modulated, thereby generating phase modulation in the interferometer, and allowing implementation of the well-known phase-generated carrier demodulation technique for fiber sensor interrogation for temperature, strain, or vibration sensing.
The features of our fiber-based Michelson or Mach-Zehnder interferometers include:
* Environmental insensitivity
* PM or non-PM single-mode fiber
* Piezo phase-modulation option
* Wide wavelength range selection
Fiber Fabry-Pérot Interferometer
A Fabry–Pérot interferometer is made of a pair of partially optical reflection surfaces. As a result of multi-path optical interference, the transmission spectrum of a Fabry–Pérot interferometer exhibits periodically resonant transmission peaks as a function of wavelength. The periodical transmission peaks provide high-resolution, well-defined, frequency references that are very useful for laser spectroscopy, laser frequency characterization, and optical frequency modulation metrology.
In high-resolution atomic or molecular spectroscopy, tunable lasers are required to scan across atomic or molecular transition lines. A high-resolution Fabry–Pérot interferometer can be used to calibrate the precision wavelength scanning of the tunable lasers. A fiber-based Fabry–Pérot interferometer can easily be implemented with fiber-pigtailed tunable lasers (including fiber-pigtailed external cavity tunable diode lasers and tunable DFB fiber lasers) for the calibration of high-precision laser wavelength tuning.
A scanning Fabry–Pérot interferometer can be used for laser mode characterization of single-frequency lasers. It can also be used for the characterization of laser frequency modulation or laser wavelength tuning. A scanning fiber Fabry–Pérot interferometer can also easily be implemented with fiber-pigtailed tunable lasers (including fiber-pigtailed external cavity tunable diode lasers and tunable DFB fiber lasers).
The features of out fiber Fabry–Pérot interferometers include:
* Environmental insensitivity
* Free-spectrum range = 1GHz
* Piezo frequency tuning
* Wide wavelength range selection