Bi-Directional Fiberoptic Coupler

Bi-Directional Fiberoptic Coupler technology for license provides efficient, low-cost bi-directional coupling of light into an optical fiber. The single integrated component can replace multiple optical elements in typical coupler designs and offers strategic advantages for application in fiberoptic communications, diode laser based instruments, optical read/write heads, and optical sensors. The coupler integrates refractive and polarizing beam splitter components into a single element offering simplified alignment, fiber insertion efficiency up to 97%, and reduced system cost.

The coupler uses refractive surfaces perpendicular to each other with either a dichroic or polarized coating on a hypotenuse surface. The refractive surfaces can be either spherical or aspheric. Normally, two of these elements are bonded together with the second element being uncoated on the hypotenuse. When a polarized coating is used, the assembly can be used to couple two diode lasers into a single fiber. If a dichroic coating is used, the coupler can be used for wavelength division multiplexing.

The coupler offers nearly lossless power summation and insertion of light from two diode lasers into a single fiber. It can be used to couple both a visible and near infrared laser into a single fiber, using the visible beam as a marker for the invisible near IR beam.

In sensor applications, the coupler can be used to insert light into a fiber and return a feedback signal. For example, a medical device might use the coupler to deliver light to a photochemical treatment site and return a feedback signal to measure response. In other instances, the feedback signal can be used to detect when the fiber tip is approaching a surface.

In the communications field, the coupler can be used as a transmitter/receiver optic on each end of a fiber.

Duncan Technologies Inc., 11824 Kemper Road Auburn, CA 95603. Tel: 530-888-6565; Fax: 530-888-6579.