Patents Assigned to Denselight Semiconductors Pte Ltd
  • Patent number: 10217718
    Abstract: A wafer-level semiconductor die attachment method includes placing a semiconductor die of a plurality of semiconductor dies at an initial placement position to overlap a sub-mount pad on a sub-mount of a pre-singulated wafer. A die pad of the semiconductor die comes in contact with a solder layer deposited over the sub-mount pad. The semiconductor die and the sub-mount include a plurality of die and sub-mount mating features, respectively. The solder layer is heated locally to temporarily hold the semiconductor die at the initial placement position. The pre-singulated wafer is reflowed, when each semiconductor die is temporarily held at the corresponding initial placement position. During reflow, each semiconductor die slides from the initial placement position and a contact is established between the corresponding plurality of die and sub-mount mating features. Thereby, each semiconductor die is permanently attached to the corresponding sub-mount.
    Type: Grant
    Filed: October 13, 2017
    Date of Patent: February 26, 2019
    Assignee: DenseLight Semiconductors Pte. Ltd.
    Inventor: Yee Loy Lam
  • Patent number: 10107975
    Abstract: A method for manufacturing an optoelectronic assembly includes attaching an optical die, a first lens, a second lens, and an optical fiber to a sub-mount. The sub-mount includes a plurality of passive alignment features which aid in the passive alignment of the optical die, the first lens, and the optical fiber for attachment. The second lens is actively aligned between the first lens and the optical fiber, based on a coupling efficiency with which an optical signal emitted by the optical die is coupled into the optical fiber through the first and second lenses. The active alignment of the second lens includes calibration of at least one of a position and a degree of tilt of the second lens.
    Type: Grant
    Filed: November 13, 2017
    Date of Patent: October 23, 2018
    Assignee: Denselight Semiconductors Pte. Ltd.
    Inventors: Yee Loy Lam, Long Cheng Koh, Kian Hin Victor Teo
  • Patent number: 6879740
    Abstract: A device for optical space switching in optical networks. The optical device comprises a broad area optical waveguide section having a number of electrodes extending over at least a portion of the length of the broad area optical waveguide section. The application of an electrical signal to an electrode causes a local change in effective refractive index of the broad area optical waveguide section, thereby causing light preferentially to propagate along a predetermined path in dependence on the configuration of the electrode. In particular the broad area waveguide device is implemented in indium phosphide (InP). Also described is a method for waveguiding in the optical device.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: April 12, 2005
    Assignee: Denselight Semiconductor PTE LTD
    Inventors: Yee Loy Lam, Yuen Chuen Chan, Peh Wei Tan, Bee Khuan Law
  • Patent number: 6845197
    Abstract: The present invention relates to a semiconductor optical tap comprising: a multimode interferometer (MMI) (6); an input waveguide (1) coupled to the MMI; a first output waveguide (2) coupled to the MMI; and a second output waveguide (3) coupled to the MMI. The first and second output waveguides (2,3) overlap (d) such that unequal portions of light are coupled from the MMI into the first and second output waveguides (2,3). The input waveguide (1) and the first and second output waveguides (2,3) may have a rib structure. They may also be adiabatically tapered waveguides. The first and second output waveguides (2,3) may have different starting widths.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: January 18, 2005
    Assignee: Denselight Semiconductors Pte Ltd
    Inventors: Yee Loy Lam, Yuen Chuen Chan, Bee Khuan Law
  • Patent number: 6833606
    Abstract: In the present invention, a semiconductor device is formed which includes an MIM capacitor located on the upper surface of a heterostructure from which the emitter, base and collector sections of a nearby HBT are defined. In this way the capacitor and HBT share a substantially common structure, with the base and emitter electrodes of the HBT fashioned from the same metal layers as the upper and lower capacitor plates, respectively. Furthermore, as the insulator region of the capacitor is formed prior to definition of the HBT structure, the dielectric material used can be deposited by means of a plasma enhanced process, without damaging the HBT structure.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: December 21, 2004
    Assignee: Denselight Semiconductor PTE LTD
    Inventors: Hiroshi Nakamura, Ting Cheong Ang, Kian Siong Ang, Subrata Halder, Geok Ing Ng
  • Patent number: 6825542
    Abstract: The present invention relates to a semiconductor photodetector. The photodetector is a waveguide photodetector, which comprises: a waveguide (1,2,3) having a III-V ridge structure including an active layer (1); a semiconductor layer (4) deposited on top of the ridge structure; and, metal detector electrodes (not shown) on the surface of the higher refractive index semiconductor layer (4). The semiconductor layer (4) has a higher refractive index than the waveguide structure (1,2,3). The ridge structure is configured to widen along the length of the waveguide (1,2,3) such that light passing through the active layer (1) of the waveguide couples more efficiently up into the higher refractive index semiconductor layer (4).
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: November 30, 2004
    Assignee: Denselight Semiconductors Pte Ltd
    Inventors: Yee Loy Lam, Yuen Chuen Chan, Chai Leng Terence Wee
  • Patent number: 6819853
    Abstract: We propose a technique for fabricating stacked photonic lightwave circuits (PLCs), with both high and low refractive index steps, comprising the use of etched PECVD dielectric layers for the light guiding structures and which are surrounded and separated by an interlayer PLC cladding (IPC) comprising a non-conformal layer of sol-gel, whose composition, refractive index and thickness can be tailored to the requirements of the device.
    Type: Grant
    Filed: September 17, 2002
    Date of Patent: November 16, 2004
    Assignee: Denselight Semiconductor Pte Ltd.
    Inventors: Yee Loy Lam, Pei Wei Tan, Hwi Siong Lim, Yuen Chuen Chan
  • Patent number: 6814500
    Abstract: Disclosed is a strain relief interface for connecting a packaged optical device and an optical fibre. The optical fibre passes through a snout bore extending from a side wall of the package. The interface comprises two moulded jackets. The first moulded jacket surrounds, and is affixed to, a sheathed section of optical fibre from which a fibre jacket has been removed. A first end of the first moulded jacket is affixed to a fibre jacket that encases an adjacent section of optical fibre. A second end of the first moulded jacket is affixed to the snout bore and to a ferrule located within the snout bore. The second moulded jacket surrounds, and is affixed to, the first moulded jacket, a portion of the fibre jacket and the snout bore. Also disclosed is a method for fabricating a strain relief interface.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: November 9, 2004
    Assignee: Denselight Semiconductor PTE Ltd.
    Inventors: Yee Loy Lam, Kian Hin Victor Teo, Poh Lin Chong
  • Patent number: 6813298
    Abstract: The layer structure of a DC-PBH laser diode consists of an n-InP substrate (51), an n-InP buffer layer (52), an undoped-InGaAsP active layer (53), a p-Inp cladding layer (54), a p-InP current blocking layer (55), an n-InP current blocking layer (56), a p-InP cladding layer (57), and a p-InGaAsP contact layer (58). An additional layer of Fe-doped InP layer (55a) creates an acceptor level (Fe3+/Fe2+) near mid-band gap. The iron impurities are deep level traps, and will make the capacitance C2 less dependent of the impurity concentration of layer (56) which is normally doped with a concentration larger than 1×1018 cm−3 to lower the leakage current from p-InP blocking layer (57) to p-InP blocking layer (55) that does not contribute to light emission. The capacitance C2 and hence the overall capacitance Cp-n-p-n will be reduced with this Fe doped InP layer (55a) and consequently the displacement current through the current blocking structure during high speed operation will be lowered.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: November 2, 2004
    Assignee: Denselight Semiconductor PTE Ltd.
    Inventors: Yuen Chuen Chan, Teik Kooi Ong, Yee Loy Lam
  • Patent number: 6807215
    Abstract: There is provided a semiconductor laser comprising a gain section and an adjacent Bragg section, wherein output laser light is emitted via a facet at an interface between air and the gain section, the Bragg section comprising a distributed reflecting structure having a length substantially greater than required to ensure single longitudinal mode operation of the laser in which the side-mode suppression ratio (SMSR) is 35 dB or more, thereby in use substantially suppressing optical feedback from a facet at an interface between the Bragg section and air, and wherein an interface between the Bragg section and the gain section is quantum well intermixed, thereby rendering the interface substantially anti-reflecting at the wavelength of the laser.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: October 19, 2004
    Assignee: Denselight Semiconductor PTE LTD
    Inventors: Yee Loy Lam, Yuen Chuen Chan, Teik Kooi Ong, Hwi Siong Lim, Lay Cheng Choo, Peh Wei Tan
  • Patent number: 6798796
    Abstract: A wavelength locked tunable laser source comprising a tunable laser source, an optical reference source characterized by a frequency spectrum with two combs of discrete components of different spacing, an optical mixing device and feedback control circuitry. An optical output of the laser source is heterodyned with an output of the optical reference source at the optical mixing device to produce an electrical signal in dependence on a difference beat frequency of the two optical outputs, the feedback control circuitry being operative to process the electrical signal to provide a feedback signal which is used to tune the wavelength of the laser source so as to minimize the beat frequency and thereby substantially lock the wavelength of the laser source to a wavelength in the spectrum of the optical reference source. The use of an optical reference source with a spectrum comprising two frequency combs provides a mechanism for determining the absolute frequency to which the laser has been locked.
    Type: Grant
    Filed: March 5, 2003
    Date of Patent: September 28, 2004
    Assignee: Denselight Semiconductor PTE LTD
    Inventors: Nakamura Hiroshi, Yuen Chuen Chan, Yee Loy Lam
  • Publication number: 20030173576
    Abstract: The present invention relates to a semiconductor photodetector. The photodetector is a waveguide photodetector, which comprises: a waveguide (1,2,3) having a III-V ridge structure including an active layer (1); a semiconductor layer (4) deposited on top of the ridge structure; and, metal detector electrodes (not shown) on the surface of the higher refractive index semiconductor layer (4). The semiconductor layer (4) has a higher refractive index than the waveguide structure (1,2,3). The ridge structure is configured to widen along the length of the waveguide (1,2,3) such that light passing through the active layer (1) of the waveguide couples more efficiently up into the higher refractive index semiconductor layer (4).
    Type: Application
    Filed: January 24, 2003
    Publication date: September 18, 2003
    Applicant: Denselight Semiconductors PTE LTD
    Inventors: Yee Loy Lam, Yuen Chuen Chan, Chai Leng Terence Wee
  • Publication number: 20030174960
    Abstract: The present invention relates to a semiconductor optical tap comprising: a multimode interferometer (MMI) (6); an input waveguide (1) coupled to the MMI; a first output waveguide (2) coupled to the MMI; and a second output waveguide (3) coupled to the MMI. The first and second output waveguides (2,3) overlap (d) such that unequal portions of light are coupled from the MMI into the first and second output waveguides (2,3). The input waveguide (1) and the first and second output waveguides (2,3) may have a rib structure. They may also be adiabatically tapered waveguides. The first and second output waveguides (2,3) may have different starting widths.
    Type: Application
    Filed: January 24, 2003
    Publication date: September 18, 2003
    Applicant: Denselight Semiconductors PTE LTD
    Inventors: Yee Loy Lam, Yuen Chuen Chan, Bee Khuan Law
  • Publication number: 20030091311
    Abstract: In the present invention, profiling of the end facet of an optical waveguide reduces the amount of reflected light propagating in the waveguide. In a conventional waveguide, the effective reflectivity experienced by light at a facet is determined by the modal content of the light and the refractive index of the waveguide (core and cladding) and other material at either side of the dielectric interface, which constitutes the facet. In the present invention, depending upon the modal content of the light, the waveguide dimensions and the refractive indices at the dielectric interfaces, we adjust the profile of the facets so that it is no longer planar and so substantially reduce the amount of reflected light propagating back along the waveguide. This reduction in “effective reflectivity” can be due to an increase in the loss experienced by any reflected light or due to an increase in the amount of light transmitted.
    Type: Application
    Filed: October 16, 2002
    Publication date: May 15, 2003
    Applicant: Denselight Semiconductors Pte Ltd
    Inventors: Yee Loy Lam, Woon Loong Daniel Leong, Yuen Chuen Chan