Quantum mechanics

Homodyne detection

Coherence (philosophical gambling strategy)

Direct-conversion receiver

Telecommunications

Envelope (radar)

Heterodyne detection

Computer science

Coherence time

Laser

Physics

Laser linewidth

Optics

Superconductivity

Interferometry

Radar

Coherence length

Beat (acoustics)

Micromachines

Delayed self-heterodyne/homodyne measurements based on an unbalanced interferometer are the most used methods for measuring the linewidth of narrow-linewidth lasers. They typically require the service of a delay of six times (or greater) than the laser coherence time to guarantee the Lorentzian characteristics of the beat notes. Otherwise, the beat notes are displayed as a coherent envelope. The linewidth cannot be directly determined from the coherence envelope. However, measuring narrow linewidths using traditional methods introduces significant errors due to the 1/

The Influence of Noise Floor on the Measurement of Laser Linewidth Using Short-Delay-Length Self-Heterodyne/Homodyne Techniques