Interferomeeter

Interferomeeter is a device designed to measure interference of coherent waves by splitting an incoming wave and recombining the paths to produce an interference, or fringe, pattern. The term appears in some technical discussions as a variant or extension of the standard interferometer, with emphasis on precise phase measurement across broad spectral ranges or with time-domain modulation.

Principle: It uses beamsplitters, mirrors, and detectors; path length difference ΔL leads to phase difference φ = (2π/λ) ΔL; fringe visibility V depends on the coherence function; detectors capture intensity I ∝ I0 [1 + V cos φ]. Modern implementations may employ fiber optics, integrated photonics, or free-space architectures; some designs incorporate phase modulators, balanced detection, or digital signal processing to extract phase with high precision.

Configurations: Mach-Zehnder, Michelson, Sagnac variants; multi-pass, or arrayed interferomeeter with multiple baselines for two-dimensional measurements.

Applications: metrology, surface topography, refractive index sensing, vibration analysis, gravitational wave–like experiments at smaller scales, interferometric spectroscopy.

Advantages: high sensitivity to path-length changes, compatibility with various wavelengths, potential for on-chip integration.

Limitations: requires coherent source; sensitive to environmental perturbations; calibration and alignment complexities; dynamic range limited by detector linearity and phase noise.

History and status: The term is much less common than interferometer; in contemporary literature most practitioners refer to interferometers unless a specific brand or variant is described. See also Interferometer, Interferometry.