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This is a more efficient process than optical parametric oscillation, and in principle can be thresholdless. In order to change the output wave frequencies, one can change the pump frequency or the phasematching properties of the nonlinear optical crystal. This latter is accomplished by changing its temperature or orientation or quasi ...
Laser linewidth from high-power high-gain pulsed laser oscillators, comprising line narrowing optics, is a function of the geometrical and dispersive features of the laser cavity. [29] To a first approximation the laser linewidth, in an optimized cavity, is directly proportional to the beam divergence of the emission multiplied by the inverse ...
Laser surgery is a type of surgery that cuts tissue using a laser in contrast to using a scalpel. [ 1 ] Soft-tissue laser surgery is used in a variety of applications in humans ( general surgery , neurosurgery , ENT , dentistry , orthodontics , [ 2 ] and oral and maxillofacial surgery ) as well as veterinary [ 3 ] surgical fields.
Optical coherence tomography is an imaging modality that uses low-coherence interferometry to obtain high resolution, depth-resolved volumetric images. OCT can be used to capture functional images of blood flow, a technique known as optical coherence tomography angiography (OCT-A). SV-OCT is one method for OCT-A that uses the variance of ...
Coherence scanning interferometry (CSI) is any of a class of optical surface measurement methods wherein the localization of interference fringes during a scan of optical path length provides a means to determine surface characteristics such as topography, transparent film structure, and optical properties.
OCTA detects moving particles (red blood cells) by comparing sequential B-scans at the same cross-sectional location.To simply put it, the backscattered light reflected back from static samples would remain the same over multiple B-scans while the backscattered light reflected back from moving samples would fluctuate.
Mode locking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds (10 −12 s) or femtoseconds (10 −15 s). A laser operated in this way is sometimes referred to as a femtosecond laser, for example, in modern refractive surgery.
To produce coherent light he passed the monochromatic light from an emission line of a mercury-vapor lamp through a pinhole spatial filter. In February 2011 it was reported that helium atoms, cooled to near absolute zero / Bose–Einstein condensate state, can be made to flow and behave as a coherent beam as occurs in a laser.