Finisar Corporation

Seagate Technology Incorporated

Subra Nagarajan

Andreas G Weber

Ramesh Sundaram

Dmitri Bannikov

Alex Fishman

Serguei Dorofeev

Robert Lee Fennelly

Jignesh H Shah

Zine Eddine Boutaghou

John Stuart Wright

Jason Wayne Riddering

Neal Frank Gunderson

Joshua Ward Christensen

Andrew Robert Motzko

Mary Cynthia Hipwell

Stefan Andrei Ionescu

Daniel Dennis Dittmer

Todd Gustavson

Antanas Daugela

Rick Pfahl Freeman

Konstantinos G Haritos

Clifton H Chang

Wei Zhao

Richard Cox

Erick J Lindquist

An adaptive guard band scheme is disclosed for a data storage device. In illustrated embodiments, the adaptive guard band scheme formats different guard band cylinders and track zeros for different heads depending upon a contact cylinder of the different heads. In an illustrative embodiment, the adaptive guard band scheme utilizes the contact cylinders for the heads and a no fly cylinder to determine track zero(s) and extended data zone(s) for select heads.

Adaptive guard band for multiple heads of a data storage device

Apparatus and method for head-disc interface (HDI) modal response monitoring. A sensing element disposed on a rigid actuator arm is mechanically impedance matched to a head-disc interface (HDI) supported by the actuator arm to resonate at a predetermined frequency corresponding to at least one disturbance associated with the HDI.

Head-disc interface (HDI) modal response monitoring

An optical connector includes a base member having a first hollow bore extending from a first end toward a second end, and a recess coaxially aligned with the first hollow bore. The recess has a first internal perimeter and a second internal perimeter. The first perimeter is smaller than said second perimeter. The base member can have a post extending up from a bottom of the recess. The first hollow bore passes through the past and terminates at an end of the post. The post can have an end that terminates substantially in alignment with at least a portion of a termination region disposed between the first internal perimeter and the second internal perimeter.

Counterbore base member for ferrule-type optical connector

Systems and methods are disclosed measuring the turn-on and turn-off times of an optoelectronic transceiver's transmitter circuitry. The method includes generating a two bit sequences from separate bit sequence generators using the same controlling pattern. The first bit sequence is transmitted through an optoelectronic device and compared with corresponding bit groups in the second bit sequence. The optoelectronic device is disabled and a count of compared bit groups is kept until the comparison indicates that the optoelectronic device is completely off. Using the count and one or more of the bit groups, a turn-off time is calculated. Alternatively, the method is used to calculate a turn-on time. The optoelectronic device is enabled and a count is kept from the time the device is enabled to when the comparison of the corresponding bit groups indicates that the optoelectronic device is completely on.

System and method of measuring turn-on and turn-off times of an optoelectronic device

Method and apparatus of attenuating an optical signal without adding extra components is presented. The drive current of the optical signal source is set to meet a predetermined bandwidth requirement and exceed a predetermined amplitude requirement. An optical isolator that is used to prevent back-reflections from reaching the optical signal source is used to achieve the desired amount of attenuation. More specifically, the invention includes controlling the attenuation by tuning an angle &#x3b8; between the transmission axis of a polarizer that is part of the optical isolator and the original polarization state of the optical signal. By increasing the angle &#x3b8;, the amount of attenuation is increased; by decreasing the angle &#x3b8;, the amount of attenuation is decreased. The invention allows continuous tuning of the angle &#x3b8;.

Continuously variable attenuation of an optical signal using an optical isolator

The present invention relates generally to an improvement in the ability of test systems to test bit processing capacities of electronic devices, and in particular an improvement in their ability to measure a signal propagation delay through an object connected to an optoelectronic device. The present invention includes determining for how long after a specific bit or bit group is transmitted by an optical transceiver the bit or bit group is received at the other end of the object connected to the optical transceiver.

System and method of measuring a signal propagation delay

A system and method for testing the jitter tolerance and signal attenuation tolerance of an optoelectronic device is disclosed. The system includes a generation circuit, delay circuit and comparison circuitry. A first sequence of bits is generated, delayed, and sent to the optoelectronic device. The optoelectronic device receives the bits and retransmits them as a second sequence to the comparison circuitry, which compares the two bit sequences to determine a bit error rate. The bit error rate is then used to determine the jitter tolerance and, in an alternate embodiment, the signal attenuation tolerance of the optoelectronic device being tested.

System and method of testing a transceiver

A magnetoresistive sensor in the magnetic storage device includes a magnetoresistive element for sensing magnetic fields carried on storage medium. A cooling device is thermally coupled to the magnetoresistive element and arranged to conduct heat in a direction away from the magnetoresistive element to thereby cool the magnetoresistive element during normal operation of the storage device.

Magnetoresistive sensor for magnetic storage system

Growing community of inventors

Livermore, CA, United States of America

Subra Nagarajan