Np Photonics, Inc.

Sergio Brito Mendes

Shibin Jiang

Yushi Kaneda

Arturo Chavez-Pirson

Thomas Nikolajsen

Dan Trung Nguyen

Ewan Wright

Nayer Eradat

Gualtiero Nunzi Conti

A multi-port optical amplifier chip has an inner cladding layer sandwiched between a pair of outer cladding layers, a plurality of active core elements disposed substantially within the inner cladding layer to receive optical signals at respective input ports and transmit amplified optical signals at respective output ports, a pair of reflecting surfaces on opposing sides of the inner cladding and at least one pump source. The pump source directs pump light into the inner cladding layer where it is confined to bounce back-and-forth across the active core elements thereby enhancing the absorption of pump light into the core elements, hence increasing gain. Greater than 5 dB over the C-band (1930 nm-1965 nm) in less than 10 cm is expected with a phosphate glass material co-doped with greater than 2 weight percent Erbium and 10 weight percent Ytterbium. A number of fiber drawing based approaches are contemplated for manufacturing the amplifiers to achieve this performance and reduce cost.

Side-pumped multi-port optical amplifier and method of manufacture using fiber drawing technologies

A compact, low-cost mid-gain Erbium Micro-Fiber Amplifier (EMFA) is provided by multi-mode pumping a micro fiber formed from a specialty multi-component glass and highly co-doped with Er:Yb. The specialty glass exhibits a much higher core absorption coefficient than standard glasses. As a result, the lower order modes are rapidly absorbed in the fiber core. The abrupt change in the mode profile perturbs the higher order modes and mode couples them into the lower order modes within a very short length of fiber, less than 20 cm. This &ldquo;absorptive mode coupling&rdquo; effect can double the absorption efficiency of a circular symmetric micro fiber and extend the length over which such a highly doped fiber can be efficiently inverted. The combination of multi-mode pumping with short fiber lengths reduces the form factor and cost of EMFAs.

Multi-mode erbium micro fiber amplifier (EMFA)

The meters of coiled silica fiber in conventional R-EDFAs is replaced with an ultra-short high-gain waveguides formed of co-doped erbium-ytterbium multi-component glass a few centimeters in length. The compact R-EDA is pumped using non-conventional multi-mode pumps that couple to the waveguide cladding. The multi-component glasses support doping concentrations of the rare-earth ions erbium and ytterbium far in excess of levels believed possible with conventional glasses. These dopant levels in combination with the reflective scheme make a compact R-EDA with sufficient amplification possible.

Reflective erbium-doped amplifier

A total internal reflection (TIR) coupler for side coupling pump light into a fiber for use in an amplifier or laser is mounted on a flat surface of the fiber's inner cladding. The TIR coupler has a reflecting surface that forms an angle of taper a with the inner cladding, which is effective to reflect pump light at a preselected angle of incidence &thgr; and satisfy a TIR condition at its reflecting surface for folding pump light into the fiber. The pump light is launched into the fiber at an angle that also satisfies a TIR condition for guiding pump light inside the inner cladding.

Growing community of inventors

Tucson, AZ, United States of America

Sergio Brito Mendes