Photonics Dictionary: P

A pathogen is a biological agent, such as a virus, bacterium, fungus, protozoan, or parasite, that causes disease in its host organism. Pathogens have the capability to invade host tissues,...

Phase contrast microscopy is an optical microscopy technique that enhances the contrast of transparent and colorless specimens, making it possible to visualize fine details and internal structures...

Abbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from endogenous chromophores or exogenous contrast agents. Light is absorbed by the...

A light therapy that utilizes nonionizing light sources, including lasers, LEDs, and broadband light, in the visible and infrared spectrum. It is a nonthermal process involving endogenous...

Photodynamic inactivation (PDI) is a therapeutic approach that utilizes the combination of light, a photosensitizer, and molecular oxygen to induce cell death or inactivate microorganisms. This...

Photoimmunotherapy (PIT) is a medical treatment approach that combines elements of phototherapy and immunotherapy to target and treat specific cells or tissues in the body. The key components of this...

Photoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It measures variations in light absorption caused by the pulsatile nature of blood...

Participates in a reaction only in the presence of light and radiant energy. Besides 3D printing, photoreactive agents also have an application in light therapy. By absorbing light, photoreactive...

A substance that increases a material's sensitivity to electromagnetic irradiation. In photodynamic therapy, a drug used to render a target tissue sensitive to laser light.

Phototheranostics, a portmanteau of "photo" (light), "therapy," and "diagnostics," refers to an emerging field that combines therapeutic and diagnostic capabilities in a single platform, often...

Phototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related to the skin or mood disorders. There are different types of phototherapies,...

The cause of some forms of laser injury in which tissue absorbs incident laser light and experiences a damaging rise in temperature. The severity of the damage is dependent on the rate of energy...

Phototoxicity refers to the harmful effects caused by exposure to light, particularly intense or ultraviolet (UV) light, on living cells or organisms. This phenomenon is often associated with the...

An instrument designed to give precise and rapid detection of changes in tumor growth as well as the location of small tumors by providing a three-dimensional picture of the tissue.

A mixture of ionized gas and metal vapor generated by impingement of the laser beam onto a material being welded or a weld joint. The plume causes absorption and/or scattering of the incident laser...