Corneal Biomechanical Analysis Using Brillouin Microscopy

The Brillouin clinical instrument is comprised of three parts: a human interface, a laser-scanning confocal microscope, and an etalon-based spectrometer. The human interface is a modified ophthalmic slit-lamp instrument with chin support and headrest. The light source is a single longitudinal mode CW laser at 780 nm. A polarizing beam splitter and quarter-wave plate assembly sends the laser beam to the human interface. To focus light into the eye, a long-working distance microscope objective is used. Brillouin scattered light from the eye is collected with a single-mode optical fiber. For spectral analysis, a two-stage VIPA-etalon spectrometer configured with the cross-axis cascade principle and the spectrum is measured on a EM-CCD camera.