Siegman

Experimental Observation of a Large Excess Quantum Noise Factor in the Linewidth of a Laser Oscillator Having Nonorthogonal Modes.

Cheng, Y. Cheng, A. Siegman, 1996, Physical review letters.

Excess spontaneous emission in non-Hermitian optical systems. II. Laser oscillators.

Siegman, 1989, Physical review. A, General physics.

Excess spontaneous emission in non-Hermitian optical systems. I. Laser amplifiers.

A. Siegman, Siegman, 1989, Physical review. A, General physics.