Amplifier Rate Equations and Operating Characteristics

Kam Y. Lau

Minoru Yamada

T. Urisu, Kenji Kajiyama, Y. Mizushima

A general operation diagram of a traveling unidirectional light amplifier is proposed by theoretical analysis, wherein different regimes are specified by a noise condition and the several threshold conditions of gain. The effects of hole burning and cross relaxation on the amplified spontaneous-emission (AES) noise and the gain saturation threshold were formulated. The transient operation diagram was determined by a numerical calculation of the rate equations in dye-laser amplifier with a rhodamine 6G methanol solution system. The numerically calculated diagram agreed well with the general analytical results.

Kyo Inoue

Optical amplification in a population-inverted medium is quantum-mechanically described, using the Heisenberg picture. Unlike conventional approaches that use a photon rate equation or a phenomenological field equation, the time evolution of the field operator, the photon number operator, and their squares are directly derived from first principles. The results give a logical theoretical base for the traditional phenomenological expressions describing quantum-mechanical characteristics of optical amplifiers.

Mark D. Rotter, Roger A. Haas