R
Roger Helkey
Researcher at University of California, Santa Barbara
Publications - 97
Citations - 2845
Roger Helkey is an academic researcher from University of California, Santa Barbara. The author has contributed to research in topics: Semiconductor laser theory & Optical switch. The author has an hindex of 26, co-authored 97 publications receiving 2696 citations. Previous affiliations of Roger Helkey include Massachusetts Institute of Technology.
Papers
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Journal ArticleDOI
Short pulse generation using multisegment mode-locked semiconductor lasers
TL;DR: In this article, a mode-locked semiconductor laser which incorporates multiple contacting segments is found to give improved performance over single-segment designs, where the functions of gain, saturable absorption, gain modulation, gain frequency, repetition rate tuning, wavelength tuning and electrical pulse generation can be integrated on a single semiconductor chip.
Journal ArticleDOI
Direct-detection analog optical links
TL;DR: In this article, state-of-the-art intensity-modulation direct-detection (IMDD) analog optical links are compared with external modulation with respect to gain, noise figure, and dynamic-range performance.
Patent
Global positioning system receiver digital processing technique
TL;DR: In this paper, a Global Positioning System (GPS) commercial receiver is provided with a digital processor that can utilize to advantage P-code modulated L1 and L2 satellite signals which have been modulated with an unknown security code.
Journal ArticleDOI
Sparse aperiodic arrays for optical beam forming and LIDAR.
TL;DR: This work analyzes optical phased arrays with aperiodic pitch and element-to-element spacing greater than one wavelength at channel counts exceeding hundreds of elements to optimize the spacing between waveguides for highest side-mode suppression providing grating lobe free steering in full visible space while preserving the narrow beamwidth.
Patent
Micro-electro-mechanical-system (MEMS) mirror device
John E. Bowers,Roger Helkey,Charles Corbalis,Robert Kehl Sink,Seung Bok Lee,Noel C. MacDonald +5 more
TL;DR: In this paper, a microelectro-mechanical system (MEMS) mirror device and methods for fabricating the same allow for a large range of angular motion for a center mirror component.