Finisar

About: Finisar is a company organization based out in Sunnyvale, California, United States. It is known for research contribution in the topics: Signal & Laser. The organization has 900 authors who have published 1523 publications receiving 22634 citations.

Digital quadrature amplitude modulation with optimized non-rectangular constellations for 100 Gb/s transmission by a directly-modulated laser.

Abstract: We study the performance of novel quadrature amplitude modulation (QAM) constellations for 100 Gb/s transmission by a directly-modulated laser. Due to the strong nonlinearity of a directly-modulated laser, rectangular constellations suffer a large penalty from their regular spacing between symbols. We present a method for synthesizing irregular constellations which position symbols more efficiently. We will demonstrate the improved performance of these novel constellations over the conventional rectangular constellation as well as the superior performance achievable with digital QAM compared to optimally bit-loaded discrete-multitone modulation.

Asymmetric rise/fall time and duty cycle control circuit

Abstract: Modules and signal control circuits configured to at least partially compensate for or adjust for asymmetric rise/fall time. The circuit may include a first input node configured to receive a first data signal and a second input node configured to receive a second data signal that is complementary of the first data signal. The circuit may also include a first stage having a first node coupled to the first input node and a second node coupled to the second input node and a second stage having a first node coupled to a third node of the first stage and a second node coupled to a fourth node of the first stage. The second stage may be configured to drive a load such as a laser. The circuit may further include a third input node configured to receive a third data signal and a fourth input node configured to receive a fourth data signal that is the complementary of the third data signal. Additionally, a control stage having a first node coupled the third input node, having a second node coupled to the fourth input node, having a third node coupled to the third node of the first stage and having a fourth node coupled to the fourth node of the first stage.

Radio frequency identifiers for providing user access to computing resources

Abstract: A system for controlling access to computing resources including an authentication device operatively associated with a computing device, the authentication device being configured to transmit an interrogation signal to a predetermined area. A computing device has at least one software application resides thereon. A wireless license device is configured to transmit license information to the authentication device in response to the interrogation signal and to allow the software application to run while the wireless license device is within the predetermined area and to prevent the software application from running when the wireless license device is not within the predetermined area.

Optical component mounting apparatus

Abstract: Embodiments of the invention provide an improved optical component mounting apparatus. In one embodiment, the invention provides an optical component mounting apparatus that provides for accurate mounting of an optical component without the use of epoxy or other affixing agents. The optical component mounting apparatus includes a body having a bore formed longitudinally therethrough. A first end of the body includes an annular aperture configured to receive an optical component therein. The diameter of the aperture is generally less than the diameter of the optical component to be inserted therein, and therefore, the aperture expands to receive the optical component. Once the aperture is expanded and the optical component inserted, the aperture is allowed to contract, which operates to mechanically secure the optical component within the apparatus.

Methods for manufacturing optical modules having an optical sub-assembly

Abstract: Methods of manufacturing optical transceiver modules using lead frame connectors that connect optical sub-assemblies to printed circuit boards are disclosed. The lead frame connector includes an electrically insulating case having a first part separated from a second part, and a plurality of conductors that are electrically isolated one from another by the electrically insulating case. Each of the plurality of conductors can form an electrical contact restrained in a fixed position with respect to the first part and a contact point extending from the second part. The electrical contact is aligned with and soldered to the leads that protrude from the back end of an optical sub-assembly. The contact points can then be connected to electrical pads on a PCB.