Optics / Photonics 101

Specular Reflection - Definition

There are two types of reflection: specular and diffuse. Specular reflection is a type of surface reflectance often described as a mirror-like reflection of light from the surface. In specular reflection, the incident light is reflected into a single outgoing direction. The name specular is derived from the Latin word speculum, meaning mirror.

19 Jun 2014

Bragg Grating - Introduction and Applications

Fiber Bragg Grating (FBG) is a type of Bragg reflector (distributed type) that is constructed as a short segment of optical fiber to reflect light of certain wavelength and transmit the rest.

29 May 2014

Photodiodes - Their Working Principles and Applications

Photodiode is a kind of light detector which involves conversion of light into voltage or current based on the mode of operation of the device. It consists of built-in lenses, optical filters, and has small or large surface areas.

29 May 2014

Photometer - Definition and References

Photometer is an instrument for measuring the light intensity or optical properties of optical sources or detectors. It operates more like a transducer which converts electric current into mechanical signal.

29 May 2014

Population Inversion - Definition and References

Population inversion is a condition of the laser medium where a system consisting of a group of molecules or atoms exists in a higher excited state with more quantum systems than that of the lower energy state of a laser transition.

29 May 2014

Radiant Flux - Explanation and References

Radiant flux is the energy per unit time that is radiated from an optical source, expressed in terms of Watts.

29 May 2014

Brewster Window - Definition and Applications

A Brewster window is an uncoated substrate that is positioned at Brewster’s angle within a laser, instead of external mirrors. This substrate acts as a polarizer such that the p-polarized light enters and exits the window without reflection losses, while the s-polarized light is reflected.

15 May 2014

An Introduction Doppler Cooling

Doppler cooling is the laser based cooling of small particles, such as ions and atoms, which are trapped during the cooling process. It also involves the spontaneous emission of photons, which generate velocity-dependent light forces through the Doppler effect.

15 May 2014

Giles Parameters - Definition and Equation

Giles parameters are used to design fiber amplifiers that are made of rare-earth-doped fibers.

15 May 2014

Free-Electron Laser - Definition and Applications

A free-electron laser is a kind of laser that employs a beam of high-speed, relativistic electrons moving freely with an optical field via a magnetic structure.

15 May 2014