Abstract: A holographic probe facilitates the measurement of radiative effects such as Raman scattering or fluorescence of a remotely disposed sample. Improving upon prior-art techniques, the probe teaches a substantially in-line path between the sample and an output optic wherein a narrowband reflective element, preferably holographically recorded, is used to fold excitation energy from an illumination path into the collection path and reject any Rayleigh scattering received from the sample. The improved configuration further allows a dispersive filtering element to be placed in the illumination path, which may be used in conjunction with spatial filtering to reject non-excitation wavelengths.

Abstract: The Raman scattering detector of this invention includes a source of collimated monochromatic illumination, a cube formed of two right angle prisms, a holographic optical element disposed between the prisms, a concentrating lens, a focusing lens and one or more photo detectors. The illuminating beam passes through the cube and is concentrated by the concentrating leans to a sample. Scattered light returned to the concentrating lens is substantially collimated upon return to the cube. The holographic optical element diffracts light at desired Raman wavelengths approximately 90 degrees without substantially affecting the original wavelength. The holographic optical element further disperses light at desired Raman wavelengths permitting them to be separated. The diffracted and dispersed wavelengths are focused on one or more detectors by the focusing lens.

Abstract: A process for producing a photochromic glass which will exhibit a brown coloration in its darkened state without a degradation in the photochromic properties of the glass taking place. The process includes the steps of forming a batch of specified components which include tin or a tin compound and subjecting the resultant batch to a series of glass-forming steps so as to develop photochromic properties in a glass article formed from the molten batch.The invention also provides a photochromic glass having silver halide crystals and tin dispersed throughout the glass, the glass having in its darkened state a brown coloration which is described in accordance with the Hunter L,a,b, Color Scale System by the rectangular region having corners defined by the (a,b) co-ordinates: (5,1), (1,5), (12,16) and (16,12), the 1/2 OD FT of the glass being 120 seconds or less.

Abstract: Fast-response photochromic boro-silicate glasses which have a half-fading time of not more than 145 secs, have silver halide crystals dispersed throughout the glass and are free from barium, comprise, in weight percentages:SiO.sub.2 --31 to 59%B.sub.2 O.sub.3 --18 to 28%Al.sub.2 O.sub.3 --8 to 20%R.sub.2 O--6 to 16%wherein R.sub.2 O represents one or more of Li.sub.2 O, Na.sub.2 O and K.sub.2 O in amounts within the ranges 0 to 3% Li.sub.2 O, 0 to 8% Na.sub.2 O and 0 to 16% K.sub.2 O, and where the content of silver, expressed as Ag.sub.2 O, lies within the range 0.05 to 0.4% by weight, while the content of halide lies within the range 0.13 to 1% by weight of the glass.Further optional constituents are MgO (up to 2.6%) and P.sub.2 O.sub.5 (up to 12%). Refractive index n.sub.D can be corrected to the standard ophthalmic value of 1.523 by additions of ZrO.sub.2, TiO.sub.2 and/or PbO.

Abstract: Fast-response photochromic boro-silicate glasses which have silver halide crystals dispersed throughout the glass and are free from barium, comprise, in weight percentages:______________________________________ SiO.sub.2 31 to 59% B.sub.2 O.sub.3 18 to 28% Al.sub.2 O.sub.3 8 to 20% R.sub.2 O 6 to 16% ______________________________________Where R.sub.2 O represents one or more of Li.sub.2 O, Na.sub.2 O and K.sub.2 O in amounts within the ranges 0 to 3% Li.sub.2 O, 0 to 8% Na.sub.2 O and 0 to 16% K.sub.2 O, and where the content of silver, expressed as Ag.sub.2 O, lies within the range 0.05 to 0.4% by weight, while the content of halide lies within the range 0.13 to 1% by weight of the glass.Further optional constituents are MgO (up to 2.6%) and P.sub.2 O.sub.5 (up to 12%). Refractive index n.sub.D can be corrected to the standard ophthalmic value of 1.523 by additions of ZrO.sub.2, TiO.sub.2 and/or PbO.