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What is Fermat’s Principle?

Editorial Team - GoPhotonics

Sep 22, 2023

Fermat’s principle, also known as the Principle of Least Time, states that light follows a path of minimum time when it travels from one point to another. It considers the quickest time to cover the path and not the shortest distance. This principle displays the connection between wave optics and ray optics. Fermat's principle was proposed by the French mathematician and physicist Pierre...read more

TagsLaws of Physics Optics

What is Laser Speckle?

Global Lasers

Editorial Team - GoPhotonics

Sep 20, 2023

When laser light hits a surface with imperfections, it creates a unique pattern of scattered light intensity. This phenomenon leads to the creation of an interference pattern known as speckles. These speckles comprise a pattern characterized by alternating bright and dark spots of varying shapes, distributed in a random manner throughout space.Laser speckle was first observed in the 1960s, shortly...read more

TagsLasers

What are Vertical-Cavity Surface-Emitting Lasers or VCSELs?

Global Lasers

Editorial Team - GoPhotonics

Sep 19, 2023

Vertical-Cavity Surface-Emitting Lasers (VCSELs) are a class of semiconductor lasers designed with a unique architecture. Unlike conventional edge-emitting lasers, VCSELs emit light perpendicular to the surface of the semiconductor chip, which results in a more efficient and precise beam. Common VCSEL wavelengths include 850 nm, 1310 nm, and 1550 nm, among others, making them suitable for various ...read more

TagsLasers Waveguides

What is Coherent Population Trapping?

Global Optics

Editorial Team - GoPhotonics

Aug 31, 2023

Coherent Population Trapping (CPT) is a quantum phenomenon that occurs in atomic systems when certain energy levels of atoms are manipulated to create a population of atoms that are "trapped" in a coherent superposition of quantum states. Coherent superposition of quantum states means that atoms are put into a special situation where they exist in a combination of different states at the...read more

TagsOptics

What are Interferometers?

Global Interferometers

Editorial Team - GoPhotonics

Aug 31, 2023

An Interferometer is a device that utilizes wave interference to make precise measurements of parameters like distance, wavelength, or small displacements. The interferometer employs the principle of interference, a phenomenon arising from the interaction of two or more waves. When the crests of two waves coincide, they exhibit constructive interference, intensifying the wave's amplitude. Conv...read more

TagsInterferometers Interferometry

What is Fraunhofer and Fresnel Diffraction?

Imaging Optics

Editorial Team - GoPhotonics

Aug 23, 2023

Diffraction of light refers to the phenomenon where light waves bend or spread out as they encounter the edge of a material or pass through a slit opening. Light behaves like a quantized wave in the electromagnetic field. When it travels, it also shows internal diffraction. Internal diffraction is the interaction of the light waves with the diffracting object or aperture, resulting in deviations f...read more

TagsOptics Imaging

What are Microlens Arrays?

Optical Components Optics

Editorial Team - GoPhotonics

Aug 8, 2023

Microlens arrays consist of arrays of small lenses (lenslets) organized in either one or two dimensions. These lenslets typically exhibit a periodic pattern, commonly square or hexagonal, with a lens pitch ranging from a few hundred micrometers to tens of micrometers or even smaller. Microlens arrays are commonly used to enhance the spatial resolution of optical systems. In imaging applications, e...read more

TagsOptics Optical Systems

What are Single Photon and Two-Photon Excitation?

Global

Editorial Team - GoPhotonics

Jul 17, 2023

Single-photon excitation and Two-photon excitation are two different mechanisms for exciting atoms or molecules to higher energy states. Single-photon excitation is the conventional method of fluorescence excitation. It involves the use of a single photon, which carries the energy required to excite a fluorophore. Two-photon excitation is a more advanced technique that allows for deeper tissue ima...read more

TagsFluorescence

What are Solid-State Lasers?

Lasers

Editorial Team - GoPhotonics

Jul 13, 2023

Solid-state lasers are a type of laser where the lasing medium is a solid material, typically a crystal or glass, rather than a liquid or gas, doped with rare earth or transition metal ions. The concept of solid-state lasers was first proposed in the 1960s. In 1960, Theodore H. Maiman showed the world the first laser, which was constructed using a ruby crystal as the special material that produced...read more

TagsLaser Modules & Systems Laser Systems Lasers

What is Photophysics?

Global

Editorial Team - GoPhotonics

Jul 13, 2023

Photophysics is a branch of physics that focuses on the intricate interactions between light and matter. It explores the fundamental processes that take place when light interacts with atoms, molecules, and solid-state materials. This field encompasses a wide range of phenomena, including absorption, excitation, emission, scattering of light, fluorescence, phosphorescence, energy transfer, photo-i...read more

TagsOptics

What is Surface Plasmon Resonance?

Global

Editorial Team - GoPhotonics

Jun 12, 2023

Surface Plasmon Resonance (SPR) is an optical technique used for the real-time measurement of molecular interactions. SPR occurs when a metal film, subjected to total internal reflection, is exposed to plane-polarized light. The resonance condition for SPR is met when photons, having the appropriate energy, interact with the metal surface at a specific angle of incidence. The incident photons tran...read more

TagsOptics Plasma Optics

What is Multiphoton Microscopy?

Imaging

Editorial Team - GoPhotonics

Jun 12, 2023

Multiphoton Microscopy is an advanced imaging technique used in biological and medical research that allows high-resolution imaging of living tissues and cells. It is a form of fluorescence microscopy that utilizes the nonlinear optical process known as multiphoton excitation. In this process, multiphoton excitation, which involves the simultaneous absorption of multiple lower-energy photons ...read more

TagsImaging Microscopes Microscopy

What is Photodynamic Therapy?

Global

Editorial Team - GoPhotonics

Jun 6, 2023

Photodynamic therapy (PDT) is a procedure in which light is used to activate a photosensitizer or PDT drug, which is a chemical agent, that eventually leads to the destruction of cancer or a diseased cell. It is a multidisciplinary approach that has seen significant growth worldwide.Basic Principle of PDTPhotodynamic therapy uses light to activate the photosensitizer or PDT drug. The drug is given...read more

TagsMedical

What is Mode Mixing?

Global

Editorial Team - GoPhotonics

May 16, 2023

Mode Mixing in LasersMode Mixing in Lasers refers to a phenomenon in which the laser output does not have a single well-defined spatial mode, but rather exhibits a mixture of different spatial modes. It leads to decreased performance and causes potentially damaging effects in lasers. Therefore, it is essential to prevent mode mixing for optimizing laser performance and ensuring safe operation.In a...read more

TagsLasers Optical Fibers

What are MEMS Optical Switches?

Fiber Optics

Editorial Team - GoPhotonics

Apr 13, 2023

Optical switches are devices that can selectively switch or route an optical signal from one fiber to another, without converting the signal into an electrical signal. They can be based on different principles such as electro-optic, thermo-optic, acousto-optic, and micro-electromechanical systems (MEMS) technology. A Micro-Electro-Mechanical System, or MEMS, refers to a micro-device or system...read more

TagsOptical Components

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Gophotonics Community

What is Fermat’s Principle?

What is Laser Speckle?

What are Vertical-Cavity Surface-Emitting Lasers or VCSELs?

What is Coherent Population Trapping?

What are Interferometers?

What is Fraunhofer and Fresnel Diffraction?

What are Microlens Arrays?

What are Single Photon and Two-Photon Excitation?

What are Solid-State Lasers?

What is Photophysics?

What is Surface Plasmon Resonance?

What is Multiphoton Microscopy?

What is Photodynamic Therapy?

What is Mode Mixing?

What are MEMS Optical Switches?

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