NONLINEAR REFRACTION AND INCREASING ABSORPTION IN HgCdTe OPTICAL BISTABILITY AT ROOM TEMPERATURE : AN EXPERIMENTAL STUDY S. CECCHI, P.M. COPPO, P. SALIERI and F.T. ARECCHI J. Phys. Colloques, 49 C2 (1988) C2-135-C2-136 DOI: 10.1051/jphyscol:1988231