What is optical low-coherence reflectometry?
An optical low-coherence reflectometer (OLCR device) is described that allows the precise and noncontact measurement of eye length. The device measures eye length both on-axis and off-axis, thus enabling the determination of eye shape, an ocular parameter thought to be important in the development of refractive error.
How LCI work?
The LCI operation is simple and reliable. It uses load-commutated, phase-controlled power thyristor technology to supply power to the stator windings of a high efficiency synchronous motor. The power circuit has a source converter, connected to the power supply and a load converter connected to the motor.
Why is low-coherence light source used in Oct?
Optical coherence tomography (OCT) is an imaging technique that uses low-coherence light to capture micrometer-resolution, two- and three-dimensional images from within optical scattering media (e.g., biological tissue). The use of relatively long wavelength light allows it to penetrate into the scattering medium.
What is LCI in electrical?
Load Commutated Inverter (LCI) is a system with an input thyristor bridge and an output thyristor bridge. The input bridge is naturally commutated by the AC supply and supplies DC current with harmonics into a large inductor.
What are the disadvantages of VSI fed synchronous motor drive?
What are the disadvantages of VSI fed synchronous motor drive? VSI synchronous motor drives might impose fewer problems both on machine as well as on the system design. A normal VSI with 180° conduction of thyristors required forced commutation and load commutation is not possible.
What is low coherence light source?
Low-coherence interferometry (LCI) is a non-contact optical sensing technology. A low-coherence light beam from an optical probe scans through a multilayer film. Note: the emitted and reflected light actually travels along the same axis (collinear scanning).
How does an optical interferometer work?
“An optical interferometer is a device in which two or more light waves are combined together to produce interference. When it is closer by half of a wavelength, a crest in one beam will correspond to a trough in the other beam, and the two light waves will exactly cancel each other, making the star disappear.
What are the different types of interferometer?
Field and linear interferometers
- Air-wedge shearing interferometer.
- Astronomical interferometer / Michelson stellar interferometer.
- Classical interference microscopy.
- Common path – Bath.
- Cyclic interferometer.
- Diffraction-grating interferometer (white light)
- Double-slit interferometer.
- Dual-polarization interferometry.
What is voltage fed inverter?
A voltage source inverter is fed by a stiff DC voltage or constant DC voltage is called Voltage Source Inverter (VSI) or Voltage Fed Inverter (VFI). In Voltage Source Inverter (VSI) we use power semiconductor switching devices in the circuit like Power BJT, Power MOSFET, IGBT having self-commutation properties.
What is VSI drive?
Definition: The voltage source inverter is defined as the inverter which takes a variable frequency from a DC supply. The voltage source inverter use self-commutated device like MOSFET, IGBT, GTO, etc. It is operated as a stepped-wave inverter or a pulse width modulation.