Patent ID: 8922283

Claim:
A wristwatch, which comprises: an atomic oscillator comprising a system for detecting beat frequencies obtained by Raman effect, wherein the atomic oscillator comprises a laser source, a cell containing cesium or rubidium and placed so as to receive a laser beam emitted from the laser source, and a beat frequency detection system that comprises a photodetector and an amplifier, which is placed so as to receive a laser beam output by the cell in order to detect a beat frequency obtained between the laser beam output by the laser source and transmitted through the cell and a laser beam induced by Raman effect within atoms in the cell, and a current source providing a laser injection current for the laser source of the atomic oscillator, a diplexer and a return link from the beat frequency detection system to the diplexer that allows a signal detected by the beat frequency detection system to be combined with the current source of the laser injection current, wherein the return link from the beat frequency detection system to the diplexer includes a phase shifter, wherein the beat frequency detection system is a system for detecting a signal i PD corresponding to the beat frequencies induced by Raman effect, with a narrow spectral content centered around a central frequency ω C , comprising at least a first inductive element L 1 which is connected to the photodetector and a parasitic capacitor C IN parallel to the photodetector, together forming a resonant circuit for selecting the signal to be detected, said resonant circuit having a resonant frequency that corresponds to the central frequency ω C .