Patents Assigned to Nexfon Corporation
  • Patent number: 6741813
    Abstract: An interleaver comprises a serial array of optical elements to which a multichannel, continuous spectrum, composite signal is input and two multichannel, non-continuous spectrum, composite signals are output. Two embodiments are disclosed. One such embodiment provides output composite signals which are spectrally symmetric in that each such non-continuous spectrum contains the same number of channels albeit of alternating center wavelengths. The other such embodiment provides output composite signals which are spectrally asymmetric in that each such non-continuous spectrum contains either a different number of channels or an equal number of channels of narrower or wider passband. Each of the preferred embodiments comprises an array of optical elements which split the input composite signal into components of different polarization states, selectively add phase shifts to some of these components and recombine them a number of times.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: May 25, 2004
    Assignee: Nexfon Corporation
    Inventors: Zhenpeng Su, Yi Qin, Hongchuan Wang, Zhouzheng Shi
  • Patent number: 6692160
    Abstract: A packaging method and apparatus that improve the yield and reliability of multi-port fiber optical devices are disclosed. The method utilizes a flexible metallic connection between a solid frame holding input and output optics (including fibers, collimators) and the main body of an optical device. Optical alignment and realignment are accomplished following the soldering and/or hermetically sealing of the entire package. A flexible connection is made with permeable material that has minimum stress memory associated with realignments and can tolerate repeated adjustment or realignment without becoming structurally unsound.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: February 17, 2004
    Assignee: Nexfon Corporation
    Inventors: Yi Qin, Charles X.W. Qian
  • Patent number: 6603906
    Abstract: An optical power monitor comprises a fiber and ferrule assembly telescopically embedded in a first glass tube enclosure and a collimating lens telescopically embedded in a second glass tube enclosure. The two glass tube enclosures are bonded together at their respective facing axial ends. The collimating lens is at a first end substantially adjacent the fiber and ferrule assembly. A second end of the lens is coated with a partially transmissive mirror surface for passing a portion of incident light to a photon detector which is bonded to the second glass tube enclosure.
    Type: Grant
    Filed: July 28, 2001
    Date of Patent: August 5, 2003
    Assignee: Nexfon Corporation
    Inventors: Yi Qin, Zhouzheng Shi, Kurt R. Francis
  • Patent number: 6574049
    Abstract: Optical interleavers and de-interleavers that can be used to combine and separate optical signals are described. These devices are based on Mach-Zehnder interferometers having one or two Gires-Toumois mirrors. The optical designs disclosed herein include several key improvements over prior arts. These improvements of interleavers enabled lower cross talk and more accurate channel center frequencies. The new designs also improve on the stability of the devices and substantially reduce the manufacturing costs. With the usage of multi-fiber collimators, a pair of interleaver and de-interleaver is fabricated using the same optical block thereby further reducing the manufacturing costs.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: June 3, 2003
    Assignee: Nexfon Corporation
    Inventors: Charles Qian, Jianying Cao, Yi Qin
  • Patent number: 6560396
    Abstract: This invention is related to method for assembling an optical attenuator to attenuate an optical beam. The method includes a step of a) collimating the optical beam from an input optical waveguide into a substantially collimated beam comprising an upper segmented-portion and a lower segmented-portion. The method further includes steps of b) transmitting the collimated onto a phase shifting means comprising at least an upper phase shifting means for generating a phase difference between the upper segmented-portion and the lower segmented-portion and c) generating a self-interference between the upper segmented-portion and the lower segmented-portion of the collimated beam and focusing the collimated beam into an output optical waveguide with an attenuation resulting from the self-interference.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: May 6, 2003
    Assignee: Nexfon Corporation
    Inventors: Mei Yan, Hongchuan Wang
  • Patent number: 6525881
    Abstract: An optical filtering element with minimized edge effects, larger clear center aperture, and thermally stable bonding area. The element consists of a modified ball lens. The glass material that comprises the ball lens can be selected from a variety of thermally matched glass specific to the intended application such as BK7, SiO2, et cetera. The lens is polished on two sides so that the polished surfaces are nearly parallel. The polished ball lens(es) are then loaded into a coating fixture and then into a coating chamber. Multiple dielectric layers are applied to one of the polished surfaces, creating a spectral modifying filter. The other side is coated with an anti-reflection coating (some applications do not require the anti-reflection coating). At the completion of the coating run, the now polished and coated ball lenses can be spectrally measured and binned for use.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: February 25, 2003
    Assignee: Nexfon Corporation
    Inventor: Kurt R. Francis
  • Patent number: 6471417
    Abstract: The present invention discloses a low-cost high power optical adapter employed to reduce the effects of the contaminants in the high power fiber optical transmission systems. The high power optical adapter uses the exactly same housing of the standard plug style single mode optical attenuators. The attenuating fiber is replaced by a TEC fiber. The TEC fiber has an MFD of more than 25 um at one end and an MFD of about 10 um at the other end that is the same as a standard single mode fiber. In the high power optical adapter, the large MFD end of the TEC fiber is fixed at the male side of the ferrule and the small MFD end of the TEC fiber is fixed at the female side of the ferrule. When the high power optical adapter is employed, the original pair of the standard optical connectors are first disconnected from the standard mating sleeve. Then each of these connectors is mounted into the female sides of a pair of the high power optical adapters.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: October 29, 2002
    Assignee: Nexfon Corporation
    Inventors: Hongchuan Wang, Mei Yan