Optics / Photonics 101

Luminous Flux - Definition and Introduction

Flux or luminous flux is a measure of total amount of energy radiated per second from a light source in all directions.

20 Jun 2014

Metastable States - Definition and Applications in Optics

Metastable state is an excited state of an atom or other system with a longer lifetime than the other excited states. However, it has a shorter lifetime than the stable ground state. Atoms in the metastable state remain excited for a considerable time in the order of 10-6 to 10-3. During metastable state, all the parameters associated with state hold stationary values. A large number of excited atoms are accumulated in the metastable state.

20 Jun 2014

Beam Profiler - Definition and Applications

Measurement of the optical beam profile is of critical importance in a number of laser applications.

20 Jun 2014

Optical Pumping - Definition and Applications

An optical fiber is a flexible and transparent material made out of glass and extruded in the form of fibers. Optical fibers are used as wave guides or light pipes for transmitting light between the two ends of the fiber. Optical fiber cables have a thickness that is slightly greater than that of human hair.

19 Jun 2014

Radiance - Deinition and Introduction

Radiance of a source is the power that is radiated from a surface within a solid angle and passing through a cross-sectional area. Radiance may be described as the power traversing at a point in a specified direction per unit area perpendicular to the direction of travel. Solid angle is the area projected on a unit sphere centered at that point. The symbol used for radiance is L having unit as Watt/ (m2sr1).

19 Jun 2014

Thermoelectric Cooling - Definition and Applications

Thermoelectric cooling is a process of eliminating heat energy from a device, component or medium with the application of constant voltage between two dissimilar semiconductors or electrical conductors.

19 Jun 2014

Radiant Intensity - Definition and Introduction

Radiant intensity may be defined as the amount of power emitted by a source in a particular direction per unit solid angle.

19 Jun 2014

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