Engineering topics
Publications and source records attributed to Pax, Paul H..
The present technology provides large mode area optical fibers engineered to have normal dispersion around 1600 nm, enabling high power Raman amplification at eye safer wavelengths. The fibers can have a main core and one or more side cores disposed relative to the main core so that modes of the main core and the one or more side cores hybridize into supermodes with modified dispersion.
The fabrication of sleeveless canes utilizes a preform with an array of glass canes in the preform. At least one tube-sleeve encircles the array of glass canes and is secured to the array of glass canes. The array of glass canes is moved into a furnace wherein the array of glass canes is heated. The furnace is maintained at a furnace temperature within the range of 2000° C. to 1700° C. and the array of glass canes is drawn from the furnace. The drawing of the array of glass canes both scales down the glass canes and elongates the glass canes. Maintaining the furnace at a furnace temperature within the range of 2000° C. to 1700° C. assures that the array of glass canes and the glass canes maintain their original shape.
An all fiber wavelength selective coupler provides wavelength selective transfer of optical energy between two or more separated waveguides. The coupler includes signal cores that are separated enough that they can be fusion spliced to standard fibers as lead-in and lead-out pigtails. A bridge between the signal cores facilitates transfer of the optical energy through a process of evanescent coupling. In one example, the bridge is formed of a series of graded index cores.
An all solid hybrid waveguiding structure provides large mode area, acceptable losses of the desired core mode and very high losses of the undesired next higher order mode in the core. Embodiments of the waveguide include a hybrid of low index barriers providing confinement by total internal reflection, and further include high index rings that support guided modes only at effective indices different from that of the desired core mode.
A class of fibers is described that have a non-circular cross section on one or both ends that can by optimized to capture the optical radiation from a laser diode or diode array and deliver the light in the same or different shape on the opposite end of the fiber. A large multimode rectangular waveguide may be provided which can accept the radiation from a high-power diode bar and transform it into a circular cross section on the opposite end, while preserving brightness.