Abstract: A system and method for monitoring the state of a crystal (C) which is suspended in a solution is disclosed which includes providing a light source (10) for emitting a beam (12) of light along an optical axis (X). A collimating lens is arranged along the optical axis for collimating the emitted beam to provide a first collimated light beam (16) consisting of parallel light rays. The solution and crystal are contained in a transparent container (18). By passing the first collimated light beam through the container, a number of the parallel light rays are deflected off of the surfaces of said crystal being monitored according to the refractive index gradient to provide a deflected beam (19) of deflected light rays. A focusing lens (22) is arranged along the optical axis for focusing the deflected rays (32, 34, 48, 50) towards a desired focal point (24a). A knife edge (24) is arranged in a predetermined orientation at the focal point; and a screen (26) is provided.

Abstract: A viewing chamber which permits observation of a sample retained therein includes a pair of double window assemblies mounted in opposed openings in the walls thereof so that a light beam can directly enter and exit from the chamber. A flexible mounting arrangement for the outer windows of the window assemblies enables the windows to be brought into proper alignment. An electrical heating arrangement prevents fogging of the outer windows whereas desiccated air in the volume between the outer and inner windows prevents fogging of the latter.

Abstract: A dual laser optical system and method is disclosed for visualization of phenomena in transparent substances which induce refractive index gradients such as fluid flow and pressure and temperature gradients in fluids and gases. According to the invention two images 68 and 70 representing mutually perpendicular components of refractive index gradients may be viewed simultaneously on screen 66. Two lasers 10 and 12 having wave lengths in the visible range but separated by about 1000 angstroms are utilized to provide beams 14 and 20 which are collimated into a beam 32 containing components of the different wave lengths. The collimated beam 32 is passed through a test volume 33 of the transparent substance. The collimated beam is then separated into components of the different wave lengths and focused on to a pair of knife edges arranged mutually perpendicular to produce and project images 68 and 70 onto screen 66.

Abstract: An optical manifold transforms a collimated beam, such as a laser beam, into a plurality of parallel beams having uniform intensity or having a desired intensity ratio. The manifold (10) comprises an optical substrate (12) coated on its rear surface (13) with a fully reflective layer (14) and on its front surface (15) with a partially reflecting layer (20) having a reflectivity gradient. An input collimated beam (30) entering the rear surface (13) and impinging on the front surface (14) will be reflected, multiple (32-40) between the front and rear surfaces producing a plurality of parallel beams (42, 44, 46, 48) that emerge from the front surface. The intensities of the emerging beams will have a relationship that depends on the reflectivity (R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5) of the front surface at the points where the beams emerge. By properly selecting the reflectivity gradient, the emerging beams will have uniform intensity or a desired intensity ratio.