The majority of linear-optical nondestructive implementations of universal quantum gates are based on single-photon resolving detectors. We propose two implementations, which are nondestructive (i.e., destroying only ancilla states) and work with conventional detectors (i.e., those which do not resolve number of photons). Moreover, we analyze a recently proposed scheme of Wang et al. [J. Opt. S...

We show that a beam splitter of reflectivity one-third can be used to realize a quantum phase gate operation if only the outputs conserving the number of photons on each side are post-selected. The main difficulty in realizing quantum computation and quantum information processing for single photon qubits is the optical implementation of controlled interactions between individual qubits. A dete...

The main difficulty in realizing quantum computation and quantum-information processing for single photon qubits is the optical implementation of controlled interactions between individual qubits. A deterministic interaction between separate photons would require the ability to apply strong nonlinearities during well-defined time intervals @1#. At present, there are still many technological dif...

Latching optical switches and optical logic gates with AND and OR functionality are demonstrated for the first time by the monolithic integration of a vertical cavity lasers with depleted optical thyristor structure. The thyristors have a low threshold current of 0.65 mA and a high on/off contrast ratio of more than 50 dB. By simply changing a reference switching voltage, this single device ope...

In this paper, we propose the construction of two code generators for optical ZCZ codes of Zcz = 4n−2 with positive n and Zcz = 1 using the Sylvester-type Hadamard matrix, which are called ROM-type and non ROM-type code generators. The optical ZCZ code is a set of pairs of binary and bi-phase sequences with zero correlation zone. An optical code division multiple access (CDMA) system using opti...

Variable rate application of fertilisers with traditional spinner-type spreaders is known to suffer from spread pattern uniformity variability as a function of application rate. To demonstrate this variability, simulations using models from the literature were carried out for two cases: (1) a dual disc spreader with segment-type feed gates; and (2) a single disc spreader with conical feed gates...