
Francis YuPennsylvania State University | Penn State · Department of Electrical Engineering
Francis Yu
Doctor of Engineering
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431
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Publications (431)
I will begin with the nature of our temporal (t > 0) universe, since without temporal space there would be no gravitation force because gravitational field cannot be created within an empty space. When we are dealing with physical realizability of science, Einstein’s relativity theories cannot be ignored since relativistic mechanics is dealing with...
Schrödinger’s quantum mechanics is a legacy of Hamiltonian’s classical mechanics. But Hamiltonian mechanics was developed from an empty space paradigm, for which Schrödinger’s equation is a timeless (t = 0) or time-independent deterministic equation, which includes his fundamental principle of superposition. When one is dealing Schrödinger equation...
One important aspect of our universe is that one cannot get something from nothing; there is always a price to pay. In this article we show that every bit of information is limited by a quantum unit. Since we are communicating within a temporal subspace, this unit can be equivalently described as a quantum limited subspace (QLS), as imposed by the...
This book shows there is a profound connection between information and entropy. Without this connection, information would be more difficult to apply to science. This book covers the connection and the application to modern optics and radar imaging. It shows that there exists a profound relationship between Einstein’s relativity theory and Schröing...
Gravitation is one of the most intriguing forces in space that govern all the interstellar spectacles motion in this universe. In this article we have shown there is a profound relationship between gravitational fields with respect to its converted energy. Since time is an inevitable element in every aspect of science; we have developed a partial d...
Light is not just the major source of energy that supports life and it is also a very viable information carrier. In this article, we showed that there is an intimate relationship between information and light as a carrier. We discussed the Uncertainty Principle of Heisenberg as related to information, in which we showed that every bit of informati...
Light is not just the major source of energy that supports life and it is also a very viable information carrier. In this article, we showed that there is an intimate relationship between information and light as a carrier. We discussed the Uncertainty Principle of Heisenberg as related to information, in which we showed that every bit of informati...
The original purpose for the development of holography was mainly to reproduce a true three-dimensional imagery by means of wave front reconstruction process. However, since the rediscovery, it has offered a much wider spread of application beyond its legacy!
We shall discuss the origin, the development, and the future of holography. We shall show that basically there are two types of holography, namely the transmission-type of Leith and the reflection-type of Denisyuk. Although the original purpose for developing holography was to produce 3D imageries, it has a much wider domain of application far beyo...
In this paper, we present a hybrid optical neural network using a high resolution video monitor as a programmable associative memory. The superior resolution and the number of gray levels of the video monitor lead to the implementation of a larger number of neurons and a larger dynamic range. The system operates in a high speed asynchronous mode du...
Directional sensing is a novel sensing technology which can sense not only the physical and chem- ical change of an analyte but also its changing direction. In this paper, an optical fiber method for directional sensing is mathematically analyzed and the corresponding optical sensing architecture is proposed to perform directional sensing based on...
Every invention and discovery has its own roots. This article will describe my personal experiences and encountered with Emmett Leith; as an inventor and his technological break through for the discovery of Laser-Holography. The legacy of his discovery, outgrowth from, and development, will also be shown. A tribute to Yuri Denisyuk, who has just pa...
Every invention and discovery has its own roots. This article will describe my personal experiences and encountered with Emmett Leith; as an inventor and his technological break through for the discovery of Laser-Holography. The legacy of his discovery, outgrowth from, and development, will also be shown. A tribute to Yuri Denisyuk, who has just pa...
A simple and intelligent technique of reducing the zero-order
diffraction in an optical spectrographic processor is discussed and the
corresponding nonbias optical architecture, by which spectrograms can
indeed be obtained, is proposed. Reduction of zero-order diffraction in
a Fourier optical system arises from the removal of the dc bias, which
is...
An efficient and secure algorithm for random phase mask generation used in optical data encryption and transmission system is proposed, based on Diffie-Hellman public key distribution. Thus-generated random mask has higher security due to the fact that it is never exposed to the vulnerable transmitting channels. The effectiveness to retrieve the or...
YX Liu Bo Wang YW Fu- [...]
Francis Yu
Optical spectrographic processing systems have been shown to be the most widely used techniques for time-varying signals that usually contain very distinct characteristics in spectral distributions and are difficult to categorize in time (spatial) domain. In this paper., an optical architecture for spectrograph generation, by which time-varying sig...
Bo Wang YW Fu YX Liu- [...]
Francis Yu
In this paper we report the design and implementation of a multimode fiber sensing technique for displacement sensing. To exploit the spatial information contents for sensing, a multimode fiber specklegram sensor with a hetero-core fiber structure is used. The sensor utilizes the inner product of multimode fiber speckle fields. which is highly sens...
Optical windows have been widely used in optical spectrographic processing system. In this paper, various window profiles, such as rectangular, triangular, Hamming, Hanning, and Blackman etc., have been investigated in detail, regarding their effect on the generated spectrograms, such as joint time-frequency resolution tw, the sidelobe amplitude at...
Thermal electron dynamics at the interfaces of thin gold film/ferroelectric lithium niobate (LiNbO3) is studied by using step-function type laser irradiation. Our measurements reveal an anomalous transient optical transmission fluctuation caused by thermal electron dynamics at the interfaces. To our knowledge, such phenomenon and its theoretical ex...
In this paper, a unique chemical sensing method that employs the spatial information of a hetero-core fiber structure is presented. The sensing system includes a He-Ne laser, a hetero-core fiber structure, and a charge-coupled device camera to detect the fiber specklegram generated by the hetero-core fiber structure. The change in chemical environm...
Optical window functions have been widely used in optical spectrographic processing system. In this paper, the influence of different window functions such as Blackman, Hanning and rectangular windows on the spectrographic quality is analyzed and compared quantitatively in terms of joint time-frequency resolution and sidelobe amplitude attenuation....
Although multimode fiber has a large space-bandwidth product (roughly equal to the number of modes), transmitting spatial signals by using a fiber is rather difficult. Conventional sensing schemes for fiber chemical sensors are based on the intensity and/or spectroscopic absorption or emission of fiber evanescent field of multimode fiber. However,...
Fabrication of digital sinusoidal gratings and precisely controlled diffusive flats and their application to calibration-based highly accurate phase-shifting projected fringe profilometry are presented. The main advantages of using digital sinusoidal gratings are (1) high geometrical accuracy (< 1 μm); (2) high contrast ratio; and (3) very low high...
An adaptive optical neuro-computing (ONC) using inexpensive pocket size liquid crystal televisions (LCTVs) had been developed by the graduate students in the Electro-Optics Laboratory at The Pennsylvania State University. Although this neuro-computing has only 8x8=64 neurons, it can be easily extended to 16x20=320 neurons. The major advantages of t...
Optical fibers have been widely used for transmitting temporal signal. However, the transmission of spatial signal has not been fully exploited. Although multimode fiber has a large space-bandwidth product (roughly equal to the number of modes), transmitting spatial signals by using a fiber is rather difficult. When a laser beam is launched into a...
As we know about it, the more we try to learn, the more we cannot learn. The thought of learning is quite different from college to college, and from person to person. In this paper, I shall discuss some of the major differences in the thoughts of learning (or rather education), as from the point of view of artificial neural network. By the virtues...
This chapter begins with a discussion on the fundamental coherence theory of light. Spatial coherence is primarily governed by the source size and temporal coherence is governed by the spectral bandwidth of the source. The concept of combining the optical system with its electronic counterparts is rather natural as a means of applying the rapid pro...
Optical information processing can perform a myriad of signal processing
operations. It is primarily due to the complex amplitude processing
capability. Optical information processors are capable of performing
one- or two-dimensional operations using simple linear operators.
However, it would not happen without the support of coherent property of
i...
Applications of spatial light modulators to telecommunication systems are reviewed. In particular, optical cross connect (OXC) that uses 2D spatial light modulator for addressing an input beam from N input beams to a specific output fiber in N output fibers will be discussed.
Contributors; Preface; 1. Pattern recognition with optics Francis T. S.
Yu and Don A. Gregory; 2. Hybrid neural networks for nonlinear pattern
recognition Taiwei Lu; 3. Wavelets, optics, and pattern recognition Yao
Li and Yunglong Sheng; 4. Applications of the fractional Fourier
transform to optical pattern recognition David Mendlovic, Zeev Zalesky...
A one-step method for recording color information on a monochrome transparency using a linear tricolor sampling pattern is proposed. It is shown that the method avoids color-cross-talk, moire fringes, and marginal resolution loss. The linear tricolor sampling pattern is described in detail as well as a method for computer generating the tricolor gr...
In this paper we shall begin our discussion with the relationship between optics and humans, in which we see that light has indeed provided us with a very valuable source of information. A general optical communication concept is discussed, in which we see that a picture is indeed worth more than a thousand words. Based on Shannon's information the...
Questions
Question (1)
Answer: use you creative-logical thinking. you may find a good solution. Do not be a good follower but be a good exploder. For example, the objective of an applied scientist is looking for thing "how" it works, however for a fundamental scientist is searching for thing "how" it works. But statistically, applied scientist was most of the time "right", yet for fundamental scientist was most of the time "wrong".