Abstract: The disclosed superconducting multipole RF filter comprises a multiplicity of coupled circular disk resonators designed for operation in the TM 010 mode. The disk resonators are arranged in a co-axial stack, with a circular metal spacer sandwiched between any two neighboring disk resonators. Each metal spacer has a central through-aperture, with a conductive member disposed in the through-aperture and electrically connecting the two neighboring disk resonators that are sandwiching a given metal spacer. A disk resonator comprises two circular members, each circular member comprising a circular dielectric substrate, exemplarily a LaAlO.sub.3 wafer. Superconducting layers (typically YBCO) are disposed on each major surface of the substrate. The two members are joined together such that conductive layers (typically gold) electrically connect the two outside superconducting layers. The disclosed RF filter has good power handling capability, is compact, has good heat removal and relatively simple tuning.
Type:
Grant
Filed:
August 21, 1998
Date of Patent:
September 5, 2000
Assignees:
Lucent Technologies Inc., Massachusetts Inst. of Technology
Inventors:
Alfredo Carlos Anderson, Zhengxiang Ma, Paul Anthony Polakos, Hui Wu
Abstract: An optical wavelength converter is provided that utilizes an optical interferometer configured to efficiently and rapidly shift the frequency of an optical signal and to automatically separate a pump signal from the optical signal and a frequency-shifted signal. The wavelength converter is configured with a signal port for accepting an input optical signal, of a first wavelength, to be processed for producing an output signal of a second wavelength, and a pump port for accepting a laser pump signal of a pump wavelength. An optical interferometer is connected to the signal and pump ports to separately receive the input signal from the signal port and a pump signal from the pump port and to inject each received signal independently into a nonlinear medium. In the nonlinear medium, the input and pump signals nonlinearly interact via a nonlinear optical property of the nonlinear medium to generate an output conjugate signal of a second wavelength.
Abstract: A fiber laser for producing high energy ultrashort laser pulses, having a positive-dispersion fiber segment and a negative-dispersion fiber segment joined in series with the positive-dispersion fiber segment to form a laser cavity. With this configuration, soliton effects of laser pulse circulation in the cavity are suppressed and widths of laser pulses circulating in the cavity undergo large variations between a maximum laser pulse width and a minimum laser pulse width during one round trip through the cavity. The fiber laser also provides means for modelocking laser radiation in the laser cavity, means for providing laser radiation gain in the laser cavity, and means for extracting laser pulses from the laser cavity.
Type:
Grant
Filed:
April 22, 1996
Date of Patent:
April 1, 1997
Assignee:
Massachusetts Inst. of Technology
Inventors:
Kohichi R. Tamura, Erich P. Ippen, Hermann A. Haus, Lynn E. Nelson, Christopher R. Doerr