There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Microwave photonics, which brings together the worlds of radiofrequency engineering and optoelectronics, has attracted great interest from both the research community and the commercial sector over the past 30 years and is set to have a bright future. The technology makes it possible to have functions in microwave systems that are complex or even not directly possible in the radiofrequency domain and also creates new opportunities for telecommunication networks. Here we introduce the technology to the photonics community and summarize recent research and important applications.

Microwave photonics combines two worlds

Course Description This is an advanced course in which we explore the field of Statistical Optics. Topics covered include such subjects as the statistical properties of natural (thermal) and laser light, spatial and temporal coherence, effects of partial coherence on optical imaging instruments, effects on imaging due to randomly inhomogeneous media, and a statistical treatment of the detection of light. Development of this more comprehensive model of the behavior of light draws upon the use of tools traditionally available to the electrical engineer, such as linear system theory and the theory of stochastic processes.

http://ieeexplore.ieee.org/iel5/3/23094/01073023.pdf

Statistical optics

Broadband and low loss capability of photonics has led to an ever-increasing interest in its use for the generation, processing, control and distribution of microwave and millimeter-wave signals for applications such as broadband wireless access networks, sensor networks, radar, satellite communitarians, instrumentation and warfare systems. In this tutorial, techniques developed in the last few years in microwave photonics are reviewed with an emphasis on the systems architectures for photonic generation and processing of microwave signals, photonic true-time delay beamforming, radio-over-fiber systems, and photonic analog-to-digital conversion. Challenges in system implementation for practical applications and new areas of research in microwave photonics are also discussed.

Microwave Photonics

High-sensitivity optical receivers are key elements for multi- Gbit/s-data-rate optical transmission systems. P-I-N-HEMT optical receivers achieve lowest noise performance by using reactive noise tuning at the input.1 However, current optical receiver designs are restricted to a limited number of purely inductive noise-matching networks. This has constrained the design potential of these receivers. Moreover, they have been based on simple noise representations of devices that are difficult to characterize accurately at microwave frequencies. In this work we report a new synthesis design procedure that has resulted in new classes of noise-matching network topology. The technique is also based on accurate noise-figure data. This has resulted in ultralow noise and wideband receiver operation.

New low-noise tuned P-I-N-HEMT optical receiver for 10-Gbit/s signal detection

Stress fluctuations and optical coherence of erbium in doped fibers

Recently we have proposed a dispersion controlled spectrum slicing technique, which provides both spectrum slicing of the broadband source and phase control function that impresses localized dispersion for the optical slices. In this paper, we extend this earlier concept by deriving transfer functions and investigating the performance of the dispersion controlled spectrum sliced microwave photonic signal processor for various slice characteristics. Through analysis, simulation and experimental results, we demonstrate that the RF filter performance at high frequency of operation can be greatly enhanced, for arbitrary spectrum slice shapes, slice bandwidths and various filter free spectral range values.

Performance investigation of a dispersion controlled spectrum sliced microwave photonic filter with various slice characteristics

Photonic signal processing offers the prospect of realising extremely high multi-GHz sampling frequencies, overcoming inherent electronic limitations. These processors provide new capabilities for realising high time-bandwidth operation and high-resolution performance. In-fibre signal processors are inherently compatible with fibre optic microwave systems that can integrate with wireless antennas, and can provide connectivity with in-built signal conditioning. Recent new methods in wideband signal processors including photonic mixers, beamforming elements for phased arrays, and microwave photonic filters with ultra-wideband and adaptive processing capability, are presented.

Advances in ultra-wideband and adaptive microwave photonic signal processors

Methods for wideband all-optical microwave photonic signal processing without coherent interference limitations are described. They are based on a single wavelength modulation technique. These signal processors provide new capabilities for the realisation of high time- bandwidth operation and high signal-to-noise ratio performance. Tunable signal processors using wavelength control are discussed. A new structure based on a single wavelength cross gain modulation technique for realising multiple-tap coherence-free signal processors is also presented. Experimental results are presented that demonstrate coherence- free notch filtering with deep notches, a continuously tunable equivalent negative-tap notch filter response, and an equivalent multiple-tap notch filter response.

/pdf/microwave-photonic-signal-processing-without-coherent-y0alyuyo1l.pdf

Robert A. Minasian

Papers

New low-noise tuned P-I-N-HEMT optical receiver for 10-Gbit/s signal detection

Stress fluctuations and optical coherence of erbium in doped fibers

Performance investigation of a dispersion controlled spectrum sliced microwave photonic filter with various slice characteristics

Advances in ultra-wideband and adaptive microwave photonic signal processors

Microwave Photonic Signal Processing without Coherent Interference Limitations