Lasers and Amplifiers

Abstract

The laser is the key component in any quantum optics experiment. The performance of a laser can be described by the following parameters: optical power, spatial mode structure, output wavelength, frequency spectrum, and noise spectrum. The spatial properties of the laser beams are determined by the properties of the optical resonator. Lasers are available that produce output beams, which are very close to the theoretical limit. In order to determine the dynamics of the fluctuations of the laser system, a quantum model is required. Diode lasers use the band gap in doped semiconductor materials to produce optical gain directly from an electrical current. The chapter focuses on continuous‐wave lasers since they are very common in quantum optics experiments, in precision metrology. It considers the theoretical limits to amplification of quantum limited light and discusses the theory of the non‐linear interaction. The chapter discusses the measurement‐based quantum amplifiers based on electro‐optic feed forward and heralded devices based on photon counting.