5,700 research outputs found
ATS SSB AFC carrier offset study Final report, 13 Apr. - 27 Jul. 1966
Range of Applications Technology Satellite Single Sideband Automatic Frequency Control /ATS SSB AFC
Development of SSB/DSB auxiliary time division multiplexer and demultiplexer Final report, 14 Jun. 1967 - 19 Feb. 1968
Design and performance of single sideband-double sideband auxiliary time division multiplexer prototype and demultiplexer breadboard mode
Reversible Quantum Interface for Tunable Single-sideband Modulation
Using Electromagnetically Induced Transparency (EIT) in a Cesium vapor, we
demonstrate experimentally that the quantum state of a light beam can be mapped
into the long lived Zeeman coherences of an atomic ground state. Two
non-commuting variables carried by light are simultaneously stored and
subsequentely read-out, with no noise added. We compare the case where a
tunable single sideband is stored independently of the other one to the case
where the two symmetrical sidebands are stored using the same EIT transparency
window.Comment: 4 pages, 6 figure
Study of an electro-optic modulator capable of generating simultaneous amplitude and phase modulations
We report on the analysis and prototype-characterization of a dual-electrode
electro-optic modulator that can generate both amplitude and phase modulations
with a selectable relative phase, termed a universally tunable modulator (UTM).
All modulation states can be reached by tuning only the electrical inputs,
facilitating real-time tuning, and the device is shown to have good suppression
and stability properties. A mathematical analysis is presented, including the
development of a geometric phase representation for modulation. The
experimental characterization of the device shows that relative suppressions of
38 dB, 39 dB and 30 dB for phase, single-sideband and carrier-suppressed
modulations, respectively, can be obtained, as well as showing the device is
well-behaved when scanning continuously through the parameter space of
modulations. Uses for the device are discussed, including the tuning of lock
points in optical locking schemes, single sideband applications, modulation
fast-switching applications, and applications requiring combined modulations.Comment: 12 pages, 8 figures, 1 tabl
Active stabilisation of single drive dual-parallel Mach-Zehnder modulator for single sideband signal generation
Presented is a study on a single-drive dual-parallel Mach-Zehnder modulator implementation as a single sideband suppressed carrier generator. High values of both extinction ratio and sidemode suppression ratio were obtained at different modulation frequencies over the Cband. In addition, a stabilisation loop had been developed to preserve the single sideband generation over time
Terahertz bandwidth photonic Hilbert transformers and implementations in ultra wideband single-sideband filters
Planar Bragg grating based photonic Hilbert transformers (PHTs) with THz bandwidths are proposed and practically demonstrated. An X-coupler, PHT, and a flat-top reflector are incorporated, demonstrating 2THz all-optical single-sideband filters. Devices are fabricated via a direct UV grating writing technique on a silica-on-silicon platform
Radio-frequency transparent demodulation for broadband hybrid wireless-optical links
A novel demodulation technique which is transparent to radio-frequency (RF) carrier frequency is presented and experimentally demonstrated for multigigabit wireless signals. The presented demodulation technique employs optical single-sideband filtering, coherent detection, and baseband digital signal processing. Multigigabit wireless signal demodulation of 1.25-Gbaud quadrature phase-shift-keying modulated data at 40- and 35-GHz RF carrier frequency is experimentally demonstrated using the proposed demodulation scheme
Application of optical single-sideband laser in Raman atom interferometry
A frequency doubled I/Q modulator based optical single-sideband (OSSB) laser
system is demonstrated for atomic physics research, specifically for atom
interferometry where the presence of additional sidebands causes parasitic
transitions. The performance of the OSSB technique and the spectrum after
second harmonic generation are measured and analyzed. The additional sidebands
are removed with better than 20 dB suppression, and the influence of parasitic
transitions upon stimulated Raman transitions at varying spatial positions is
shown to be removed beneath experimental noise. This technique will facilitate
the development of compact atom interferometry based sensors with improved
accuracy and reduced complexity
Simple planar Bragg grating devices for photonic Hilbert transform
Hilbert transformers are important devices widely used in information processing and signal analysis in the electronic domain. For example, for spectral efficiency improvement, it is used to construct the analytic signal for single sideband (SSB) modulation from a real signal. Photonic Hilbert transformers (PHTs) are proposed for a similar range of applications and would allow the direct processing of optical signals at bandwidths far beyond current electronic technologies
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