Search results
Results from the WOW.Com Content Network
Laser surgery used in hemorrhoidectomy, and is a relatively popular and non-invasive method of hemorrhoid removal. Laser-assisted liver resections have been done using carbon dioxide and Nd:YAG lasers. The ablation of liver tumors can be achieved by selective photovaporization of the tumor. Endoscopic laser lithotripsy is a safer modality ...
Adaptive optics ( AO) is a technique of precisely deforming a mirror in order to compensate for light distortion. It is used in astronomical telescopes [1] and laser communication systems to remove the effects of atmospheric distortion, in microscopy, [2] optical fabrication [3] and in retinal imaging systems [4] to reduce optical aberrations.
Frequency-resolved optical gating ( FROG) is a general method for measuring the spectral phase of ultrashort laser pulses, which range from sub femtosecond to about a nanosecond in length. Invented in 1991 by Rick Trebino and Daniel J. Kane, FROG was the first technique to solve this problem, which is difficult because, ordinarily, to measure ...
GreenLight Laser Therapy has been increasingly performed as an alternative to transurethral resection of the prostate in order to treat benign prostatic hyperplasia, with several studies demonstrating comparable results with fewer side effects and complications. Typically, it is an outpatient procedure which provides immediate relief of lower ...
Aberration (astronomy) A diagram showing how the apparent position of a star viewed from the Earth can change depending on the Earth's velocity. The effect is typically much smaller than illustrated. In astronomy, aberration (also referred to as astronomical aberration, stellar aberration, or velocity aberration) is a phenomenon where celestial ...
Roof prism. A roof pentaprism used in Single-lens reflex cameras; the lower right face is the roof ( dach ). A roof prism, also called a Dachkanten prism or Dach prism (from German: Dachkante, lit. "roof edge"), is a reflective prism containing a section where two faces meet at a 90° angle, resembling the roof of a building and thus the name.
The word laser is an anacronym that originated as an acronym for light amplification by stimulated emission of radiation. [1] [2] The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow.
Greenhouse–Geisser correction. The Greenhouse–Geisser correction is a statistical method of adjusting for lack of sphericity in a repeated measures ANOVA. The correction functions as both an estimate of epsilon (sphericity) and a correction for lack of sphericity. The correction was proposed by Samuel Greenhouse and Seymour Geisser in 1959.