Waveguide-containing communications and sensing systems

US4820016A · kind A · utility

Assignee

• American Telephone and Telegraph Company, AT&T Bell Laboratories · US

Inventors

• Leonard G. Cohen · Matawan, US
• John Hegarty · Dublin, IE

Key dates

• Filing date: Feb 21, 1986
• Grant date: Apr 11, 1989
• Expiry date: Feb 21, 2006

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F1/011
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An optical system, including a waveguide such as an optical fiber, in which optical signals are noninvasively coupled into the waveguide at any point along the length of the waveguide, is disclosed. This is achieved by coupling substantially constant intensity electromagnetic radiation into the waveguide, and then impinging upon the waveguide a directed beam of energy, such as electromagnetic radiation or heat, from an energy source. Alternatively, the waveguide is impinged upon by a combination of an energy beam and a stimulus, e.g., a temperature change. The energy beam, or energy beam and stimulus, induce at least partial absorption of the guided, substantially constant intensity electromagnetic radiation by radiation-absorbing material in the waveguide, to produce the desired optical signal.