OPTICAL INSTABILITIES AND COHERENCE IN THE FREE-ELECTRON-LASER H. Al-Abawi, H. Fang, S. Fu, J. K. McIver, G. T. Moore et M. O. Scully J. Phys. Colloques, 44 C1 (1983) C1-377-C1-378 DOI: 10.1051/jphyscol:1983135