Review Article

Feedback Control in Quantum Optics: An Overview of Experimental Breakthroughs and Areas of Application

Figure 2

Simplified schematics of a cold damping feedback loop in optomechanics: the cavity output is monitored by phase-sensisitve homodyne detection at the frequency of a cavity mode which is optomechanically coupled to a material oscillator (in this particular depiction, a trapped bead in a levitating setup [75ā€“77]). The measured current is then fed back to the laser through an electro-optical modulator, controlling the position and slope of the trapping potential based on the homodyne monitoring.
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