Patents by Inventor Muhammad Ashrafal Alam

Muhammad Ashrafal Alam has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6560262
    Abstract: An array of VCSEL devices and a process for fabricating the VCSEL array is disclosed. The VCSEL array emits light at n different wavelengths, wherein n is at least two. A first portion of the VCSEL devices in the array emits light at a first wavelength and a second portion of the VCSEL devices emits light at a second wavelength. Each VCSEL device has an active region consisting of alternating bands of quantum wells and boundary layers bounded by top and bottom separate confinement layers. The active region is bounded by top and bottom mirrors. The length of the active region of the VCSEL devices that emit light at the first wavelength, &lgr;s1, is different from the length of the active region of the VCSEL devices that emit light at a second wavelength. The array is fabricated by forming successive layers of material on a III-V semiconductor substrate. The composition and dimensions of the individual devices are first determined from the desired emission wavelength, &lgr;sn, of the devices in the array.
    Type: Grant
    Filed: August 9, 1999
    Date of Patent: May 6, 2003
    Assignee: Triquint Technology Holding Co.
    Inventors: Muhammad Ashrafal Alam, Mark S. Hybertsen
  • Patent number: 6261857
    Abstract: A process for fabricating a waveguide with a desired tapered profile is disclosed. The waveguide has a first section with a first height and a second section with a second height. The first height is greater than the second height. The waveguide height tapers from the first height to the second height. The waveguide is a compound semiconductor material and is formed using selective area growth. In selective area growth, a dielectric mask is formed on a substrate. The dimensions of the dielectric mask are selected to provide a waveguide with the desired dimensions. The compound semiconductor material is deposited on the substrate using chemical vapor deposition. The dielectric mask affects the rate at which the compound material is deposited in areas of the substrate proximate to the mask. Therefore, the profile of the waveguide formed using the selected mask dimensions is modeled and compared with the desired profile.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: July 17, 2001
    Assignee: Agere Systems Optoelectronics Guardian Corp.
    Inventors: Muhammad Ashrafal Alam, Mark S. Hybertsen, Roosevelt People