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A new Mode Partition Noise model for VCSEL-based optical links capturing RIN and MPN via a covariance matrix is proposed and experimental parameter extraction is performed. The model removes Ogawa-Agrawal model assumptions inappropriate for VCSELs.
Phase mask encryption is proposed to improve the transmission privacy of an optical steganography system. The stealth signal carried by amplified spontaneous emission noise is encrypted by a fast changing code.
The broad bandwidth and low loss-per-unit-length of photonic links make them potentially useful for the transmission of low-noise and high-frequency analog microwave signals. Such microwave-photonic links are useful in several precision radio-frequency (RF) applications including: radar antenna remoting, synchronization of distributed RF systems, and time/frequency transfer for geo-location. However,...
We present an all optical technique to demodulate THz signals on optical carriers using a standard optical phase modulator and an RF synthesizer. Noise floor as low as −95 dBc/Hz is reached at 700 GHz.
The MODE-GAP project was established to identify the optimum fiber type for use beyond the capacity crunch. This paper will review some of the key drivers behind the project and analyze the key limits and potential improvements‥
Using modified uni-travelling carrier photodiodes that exhibit high linearity at high photocurrent we have generated a 10 GHz microwave carrier via optical frequency division with sub 500 attosecond absolute timing jitter (1Hz – 10 MHz).
InAs possesses nearly ideal material properties for the fabrication of near- and mid-infrared avalanche photodiodes (APDs). Because electron impact ionization in InAs is greatly favored over hole impact ionization [1], InAs multiplication regions exhibit several appealing characteristics, including extremely low excess noise factors and bandwidth independent of gain. These properties make InAs APDs...
Increasing noise at high gain has limited the sensitivity of conventional 1550nm avalanche photoreceivers. We demonstrate an integrated avalanche detector with multiple gain and built-in feedback mechanisms which can potentially detect single photons.
We demonstrate detection of infrared and visible wavelength photons in on-chip waveguides with high efficiency, low noise and high timing accuracy. We achieve photon-counting optical time domain reflectometry over 200 km of optical fiber.
The ability to map a wideband signal to multiple, arbitrarily spaced new frequencies was long recognized as missing capability that could lead to fundamentally new means for signal processing and channel distribution. Its simplest form, frequency conversion, has been used in the past to reconfigure the link, but was also regarded as lossy and channel-impairing process. Indeed, conventional link design...
We propose the use of a divided spectrum balanced detection (DSBD) to reduce the intensity noise in spectral amplitude coding (SAC) OCDMA systems. Simulation results show several order of magnitude improvements in bit error rate (BER) compared to the conventional balanced detection.
CMOS compatible avalanche photodiode is designed, modeled and fabricated. Calculated mean gain, avalanche breakdown voltage, excess-noise factor, as well as the measured dark-current and spectral response are reported.
A low noise 50×100 µm2 pnp pin phototransistor is presented in this paper. The phototransistor is fabricated in a 0.35 µm CMOS process. An optimized layout leads to responsivities up to 1.99 A/W and bandwidths up to 151.4 MHz. Noise measurements show a low total output current noise spectral density of only 6.67×10−24 A2/Hz for a collector current of 2 µA.
A time-of-flight range finding sensor using a monolithic integrated pnp phototransistor is presented. The phototransistor was specially adapted for the requirements of the time-of-flight application. The sensor has a fill factor of 75 % and achieves standard deviations down to 7.3 mm at 6250 fps and an incident optical power of −40 dBm.
The principle, implementation scheme and recent experimental progress of low noise optical frequency multicasting are reviewed, relying on four-mode phase-sensitive process in fiber-based parametric mixer with normal dispersion.
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