surface roughness is a significant parameter which determines the efficiency of optical components. surface damages induced by grinding strongly influence the mechanical strength and optical quality of optical glasses. it is meaningful to rapid evaluate the surface roughness through the measurement of different grinding parameters. in this study, a cup diamond wheel (d64) is used in grinding pr...

Recently, the magnetorheological (MR) polishing process has been examined asa new ultra-precision polishing technology for micro parts in MEMS applications. In theMR polishing process, the magnetic force plays a dominant role. This method uses MRfluids which contains micro abrasives as a polishing media. The objective of the presentresearch is to shed light onto the material removal mechanism u...

The interaction of laser radiation with dielectrics and metals is detected with femtosecond resolution by pump&probe techniques (t = 80 fs or 3 ps, λ = 810 nm). Even with femtosecond laser radiation melt ejection dynamics can be observed by irradiating metals like copper or aluminium using time-resolved shadowgraphy. Laser-induced melt ejection has been observed in the time range of 100 ns to 1...

Conventional material removal of BK7 optical glass will normally result in brittle fracture at the surface, generating severe subsurface damage and poor surface finish. Subsurface damages induced by grinding strongly influence the mechanical strength and optical quality of optical glasses. However, through ductile mode grinding it is possible to reduce the surface and subsurface cracks. It is m...

The design, fabrication, and properties of one of a new class of gradient-index lenses are reported. The lens is an f/2.25 GRIN singlet based on a nanolayered polymer composite material, designed to correct for spherical aberration. The light gathering and focusing properties of the polymer lens are compared to a homogeneous BK7 glass singlet with a similar f-number. The modulation transfer fun...

Conventional material removal of BK7 optical glass will normally result in brittle fracture at the surface, generating severe subsurface damage and poor surface finish. Subsurface damages induced by grinding strongly influence the mechanical strength and optical quality of optical glasses. However, through ductile mode grinding it is possible to reduce the surface and subsurface cracks. It is m...

Laser damage thresholds at 248nm of TiO,, ZrO, and HfO, thin films of h optical thickness on SQ1 quartz glass substrates are determined by the photoacoustic mirage technique. Damage thresholds correlate with the band gap energy of these materials, as determined by optical spectroscopy. It is demonstrated that the damage resistance can be raised by an additional h/2 SiO, overlayer. Damage thresh...

A method to measure the propagation loss of optical waveguides is discussed. The measurement system involves two 3 dB couplers, a CCD camera and a signal processing unit. The propagation loss measured from this technique is found to be independent of coupling conditions. The propagation properties of waveguides prepared by proton exchange (PE) in Lithium Niobate (LiNbO3) and Silver ion exchange...

In this work, grinding or microcutting tools in the form of pellets were manufactured using a bounded alumina abrasive grains. The bound used is a vitreous material containing quartz feldspars, kaolinite and a quantity of hematite. The pellets were used in glass grinding process to replace the free abrasive grains lapping process. The study of the elaborated pellets were done to define their ef...