purpose : to compare laser interferometry (li) and ultrasound a-scan in measurement of axial length ( al ) in eyes with asteroid hyalosis methods : twenty three patients with unilateral moderate to severe asteroid hyalosis determined by b-scan ultrasonography images participated in the study. the al measurements were obtained by li and ultrasound a-scan in both asteroid hyalosis and noninvolved...

The progress on laser feedback interferometry technology is reviewed. Laser feedback interferometry is a demonstration of interferometry technology applying a laser reflected from an external surface, which has features including simple structure, easy alignment, and high sensitivity. Theoretical analysis including the Lang– Kobayashi model and three-mirror model are conducted to explain the mo...

PURPOSE To examine the applicability of the recently developed laser Doppler interferometry technique for measuring the axial length of cataract eyes in a realistic clinical situation. To determine the performance of the instrument as a function of cataract grade. To compare the results to those of ultrasound methods. METHODS A total of 196 cataract eyes of 100 patients were examined. The axi...

The last few years have seen major advances in laser interferometry. The use of laser diodes whose output wavelength can be controlled by varying the injection current has led to the development of several new techniques in interferometry, as well as new methods for multiplexing fiber-interferometer sensors. New fields have also been opened up by phase-conjugate interferometers and the use of s...

Micro-channels are made over the Ag+/Na+ ion-exchanged soda-lime glass surface by interaction of an intense Ar+ laser beam and the silver ions inside the glass matrix. The Ar+ laser beam reduces the Ag+ ions inside the matrix. The Ag+ atoms aggregate into silver nano-clusters around the interaction area, inside the glass matrix. Aggregation of the silver atoms and the thermal effects of the int...

Among possible monitoring techniques, self-mixing interferometry stands out as an appealing option for online ablation depth measurements. The method uses a simple laser diode and interference is detected inside the diode cavity and measured as the optical power fluctuation by the photodiode encased in the laser diode itself. This way, self-mixing interferometry combines the advantages of a hig...

Results are now appearing from the first generation of long baseline gravitational wave detectors that use laser interferometry for motion sensing. In this short review the history of the field will be briefly discussed, and the principles of the novel laser interferometry developed will be outlined in the context of present and future instruments.

We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an independent phase counting laser interferometer. The...