backreflected

Backreflected is an adjective used in several technical domains to describe something that has been reflected back toward its origin. In general use, it can refer to light, sound, or signals that return to the source after interacting with a surface or medium.

In optics and photonics, backreflected light arises when a portion of an incident beam is reflected toward the source, typically due to partial reflections at interfaces, surface roughness, or impedance mismatches. Backreflected power is often characterized by return loss or a back-reflection coefficient and can affect measurements in systems such as lasers, interferometers, and fiber-optic links. Devices such as optical circulators and anti-reflection coatings are used to manage backreflected components.

In computer security, backreflected XSS is a form of cross-site scripting in which user-supplied input is reflected by a web application in the immediate response without proper sanitization. The reflected content appears in the HTML or JavaScript of the page, usually within a query parameter or URL fragment. Mitigation focuses on input validation, context-aware escaping, and the use of content security policies to prevent execution of injected code.

In telecommunications and electronics, backreflected signals can indicate faults or impedance mismatches and may be measured in time-domain reflectometry or similar diagnostic techniques. These reflections help identify location and nature of disruptions in cables, waveguides, and other transmission media.

Etymology-wise, backreflected combines back with reflected, conveying the notion of reflection toward the origin.