Opa

OPA is an acronym used in several distinct fields, spanning technology, government, and science. Because its meaning depends on context, it commonly refers to Open Policy Agent, the Office of Public Affairs, the Optical Parametric Amplifier, or the historical Office of Price Administration.

Open Policy Agent. Open Policy Agent (OPA) is an open-source policy engine designed to enforce access control and other policies across software systems. It provides a centralized decision point for policy decisions and uses the Rego policy language to express rules. OPA can be integrated with cloud-native platforms, including Kubernetes, API gateways, and service-mesh environments, allowing developers and operators to separate policy logic from application code and infrastructure.

Office of Public Affairs. The Office of Public Affairs (OPA) is a term used within many U.S. federal and state agencies to designate their communications arm. Responsibilities typically include issuing press releases, coordinating media briefings, handling public messaging, and advising leadership on communications strategy. The exact structure and name can vary by agency, and entities such as the White House Office of Public Affairs are notable examples at the federal level.

Optical Parametric Amplifier. In photonics, an Optical Parametric Amplifier (OPA) is a nonlinear optical device that amplifies light by transferring energy from a pump wave to a signal within a nonlinear crystal. OPAs enable tunable wavelength generation and are used in research and specialized optical systems, often in combination with ultrafast laser sources to explore broad spectral ranges.

Other historical uses. The Office of Price Administration (OPA) was a U.S. government agency from 1941 to 1947 that controlled prices and rents during World War II to curb inflation. The acronym has other, less common uses in professional communities, further emphasizing the need for contextual clarity.