Holography: an interpretation from the phase-space point of view

The formation of holograms is interpreted as the consequence of the bilinearity of the ambiguity function. Reconstruction can then be regarded as the manipulation of the ambiguity function. Specifically, we show that in the case of in-line holography, the reconstruction can be regarded as phase tomography. In this way we provide a unified picture for the formulation of both noninterferometric and interferometric phase-retrieval techniques.     

Multiple-image encryption by wavelength multiplexing

We introduce the technique of wavelength multiplexing into a double random-phase encoding system to achieve multiple-image encryption. Each primary image is first encrypted by the double phase encoding method and then superposed to yield the final enciphered image. We analyze the minimum separation between two adjacent multiplexing wavelengths through cross talk and the multiplexing capacity through the correlation coefficient. Computer simulations are performed to demonstrate the concept. This technique can be used for hiding multiple images as well.     

A Non-Linear Filtering Problem and Its Applications

For partially observed process in n-dimensional space $\[\left\{ \begin{array}{l} {\beta _i} = {\beta _0} + \int\limits_0^t {{A_1}(s,{\beta _t})ds + \int\limits_0^t {{B_1}(s,{\beta _s})d{w_s}^{(1)},} } \{\xi _i} = \int\limits_0^t {B(s,{\xi _s}){B^*}(s,{\xi _s})\varphi (s,{\beta _s})ds + \int\limits_0^t {B(s,{\xi _s})d{w_s},} } \end{array} \right.\]$ under non-Lipschitz (even discontinuous) condition, a Bayes formula different from [1] is derived (Theorem 1). By means of this formula the innovation problem for the above process under rather weak condition is solved (Theorem 2) .Then the existence of an optimal pathwise Bang-Bang control for a partially observed process with bounded controls is obtained (Theorem 4).     

Dense Coding Process with Imperfect Encoding Operations

We study dense coding under the condition that the sender’s encoding operations be imperfect. In order to formally describe the effect of the imperfect encoding operations, we use four kinds of quantum noise processes. In this way, the imperfect operation is the corresponding perfect operation followed by a quantum noise process. We show the relation among the average probability of decoding the correct information, the non-maximally entangled state, the imperfect encoding operations, and the receiver’s measurement basis.     

Existence of solutions and optimal control for reflecting stochastic differential equations with applications to population control theory *

For the d–dimensional reflecting stochastic differential equations (1) with non-smooth boundary and unbounded domain the existence of a strong solution, (weak solution) is obtained under the conditions that the coefficients are less than linear growth and they are non-Lipschitz, (and the diffusion coefficient is non-degenerate, the drift coefficient is bounded and measurable only). Moreover, the Girsanov theorem and the martingale representation theorem with respect to system (1) are also derived. Then by using the Ekeland lemma and the martingale method the existence, necessary and sufficient conditions for an optimal control and an optimal control are obtained. The results are then applied to solve an optimal control problem for a stochastic population model     

Multiple-image hiding by information prechoosing

The information inevitably lost in multiple-image hiding is discarded in advance by the operation of prechoosing information before the hiding process; thus both fidelity and multiplexing capacity can be improved significantly. Various characters of each image provide a great many possibilities for information prechoosing. The ideal low-pass filter presented with the matched encoding and hiding procedure may be one of the simplest examples of information prechoosing for generally used images. Computer simulations demonstrate its good performance, and the security is analyzed as well.     

Analysis of phase encoding for optical encryption

A phase encoded image is encrypted using the double random phase encoding technique, (DRPE). The effects of using a variable dynamic range of phase distribution during phase encoding (pre-encryption) are examined. We begin by phase encoding the input image using the full phase range, from −π to π. We perform numerically perfect encryption and we then introduce errors into the decrypting phase-keys in the form of a pseudo-random distribution (position and phase) of incorrect pixels values. By quantifying the resulting error in the attempted decryptions, for increasing amounts of error in the decrypting phase-keys, we examine the effects of reducing the phase range to, +/− (π − Δ). In this way we attempt to improve the phase encoding procedure for use with the DRPE technique. When the pixel values calculated, during an attempted decryption, fall outside the phase range used to phase encode the assigned input image, we examine different methods of redistributing the value of that pixel to an assigned value within the allowed phase range. The effects of the phase quantisation used in the keys are also examined.     

Controlled Simultaneous Teleportation and Dense Coding

We propose a teleportation protocol and a dense coding protocol. In these protocols, one sender intends to send quantum states or classical bits to two receivers through two GHZ entanglement channels. The entanglement channels are locked by the sender and the communication process is supervised by a controller. In order to obtain the messages, the receivers need the controller’s permission, and must collaborate to unlock the entanglement channels.     

碱性橙与蛋白间的特异性与非特异性作用荧光光谱比较

将碱性橙与抗体的作用、碱性橙与牛血清白蛋白(BSA)间的作用分别作为特异性作用和非特异性作用模型,采用荧光光谱法固定激发波长为280 nm,扫描不同温度下碱性橙与抗体和牛血清白蛋白两种相互作用,在300～600 nm的发射波长,比较了两种相互作用的差异.结果表明,碱性橙与抗体结合为单一的静态猝灭过程,二者之间的作用力主要为静电作用力;在溶液中,二者以摩尔比1∶1结合,结合常数为3.88×104 L/mol(25.C),3.73×104 L/mol(37.C)和2.35×104 L/mol (45.C);碱性橙距抗体分子色氨酸残基最短距离(r)为5.52 nm.碱性橙与BSA的结合也为静态猝灭,作用力为静电作用力.但碱性橙与抗体作用过程中形成了激基复合物,与BSA则不形成激基复合物.