OPTICAL HETERODYNE TECHNIQUES FOR PHOTOACOUSTIC AND PHOTOTHERMAL DETECTION H. K. Wickramasinghe, Y. Martin, D. A.H. Spear et E. A. AshJ. Phys. Colloques, 44 C6 (1983) C6-191-C6-196DOI: https://doi.org/10.1051/jphyscol:1983629