4^th International Conference on Photonics July 28-29,2016 Berlin, Germany

An optical switch may operate by mechanical means, such as physically shifting an optical fiber to drive one or more alternative fibers, or by electro-optic effects, magneto-optic effects, or other methods. Slow optical switches, such as those using moving fibers, may be used for alternate routing of an optical switch transmission path, such as routing around a fault. Fast optical switches, such as those using electro-optic or magneto-optic effects, may be used to perform logic operations; also included in this category are semiconductor optical amplifiers, which are optoelectronic devices that can be used as optical switches and be integrated with discrete or integrated microelectronic circuits.

The functionality of any switch can be described in terms of the connections it can establish. As stated in Telcordia GR-1073,  a connection is the association between two ports on a switch and is indicated as a pair of port identifiers (i, j ), where i and j are two ports between which the connection is established. A connection identifies the transmission path between two ports. An optical signal can be applied to either one of the connected ports. However, the nature of the signal emerging at the other port depends on the optical switch and the state of the connection. A connection can be in the on state or the off state. A connection is said to be in the on state if an optical signal applied to one port emerges at the other port with essentially zero loss in optical energy. A connection is said to be in the off state if essentially zero optical energy emerges at the other port.

In optics, an image-forming optical system is a system capable of being used for imaging. The diameter of the aperture of the main objective is a common criterion for comparison among optical systems, such as large telescopes. The two traditional systems are mirror-systems (catoptrics) and lens-systems (dioptrics), although in the late twentieth century, optical fiber was introduced. Catoptrics and dioptrics have a focal point, while optical fiber transfers an image from one plane to another without an optical focus. Isaac Newton is reported to have designed what he called a catadioptrical phantasmagoria, which can be interpreted to mean an elaborate structure of both mirrors and lenses.

Optical networking is a means of communication that uses signals encoded onto light to transmit information among various nodes of a telecommunications network. They operate from the limited range of a local-area network (LAN) or over a wide-area network (WAN), which can cross metropolitan and regional areas all the way to national, international and transoceanic distances. It is a form of optical communication that relies on optical amplifiers, lasers or LEDs and wave division multiplexing (WDM) to transmit large quantities of data, generally across fiber-optic cables. Because it is capable of achieving extremely high bandwidth, it is an enabling technology for today’s Internet and the communication networks that transmit the vast majority of all human and machine-to-machine information.

Photonics is an emerging technology, comparable to semiconductor technology. Many functions in technical applications are currently realised by semiconductor products. The expectation is that photonic devices will partially replace existing semiconductor devices, but on top of that will also complement these in a qualitative way. The unique characteristics of photonic devices create an additional dimension like enlarged bandwidth, energy saving and larger communication distances. In addition, photonic devices are less sensitive to interference and have unique physical characteristics.

Semiconductor lasers or laser diodes play an important part in our everyday lives by providing cheap and compact-size lasers. They consist of complex multi-layer structures requiring nanometer scale accuracy and an elaborate design. Their theoretical description is important not only from a fundamental point of view, but also in order to generate new and improved designs. The description can be done at various levels of accuracy and effort, resulting in different levels of understanding. It is common to all systems that the laser is an inverted carrier density system.

Microwave photonics is an interdisciplinary area. that studies the interaction between microwave and. optical signals, for applications such as broadband wireless. access networks, sensor networks, radar, satellite communi- cations, instrumentation, and warfare systems.

The term biophotonics denotes a combination of biology and photonics, with photonics being the science and technology of generation, manipulation, and detection of photons, quantum units of light. Photonics is related to electronics and photons. Photons play a central role in information technologies such as fiber optics the way electrons do in electronics. Biophotonics can also be described as the "development and application of optical techniques, particularly imaging, to the study of biological molecules, cells and tissue". One of the main benefits of using optical techniques which make up biophotonics is that they preserve the integrity of the biological cells being examined. Biophotonics has therefore become the established general term for all techniques that deal with the interaction between biological items and photons. This refers to emission, detection, absorption, reflection, modification, and creation of radiation from biomolecular, cells, tissues, organisms and biomaterials. Areas of application are life science, medicine, agriculture, and environmental science. Similar to the differentiation between "electric" and "electronics" a difference can be made between applications, which use light mainly to transfer energy via light (like Therapy or surgery) and applications which excite matter via light and transfer information back to the operator (like diagnostics). In most cases the term biophotonics is only referred to the second case.

Nanophotonics or Nano-optics is the study of the behavior of light on the nanometer scale, and of the interaction of nanometer-scale objects with light. It is a branch of optics, optical engineering, electrical engineering, and nanotechnology. It often (but not exclusively) involves metallic components, which can transport and focus light via surface plasmon polaritons. The term "nano-optics", just like the term "optics", usually concerns ultraviolet, visible, and near-infrared light (free-space wavelength around 300-1200 nanometers).

Optical interconnect is a way of communication by optical cables. Compared to traditional cables, optical fibers are capable of a much higher bandwidth, from 10 Gbit/s up to 100 Gbit/s. The technology is currently being introduced as a way to link computers to mobile devices, as well as on motherboards and devices within computers.

Electro-optical sensors are electronic identifiers that change over light, or an adjustment in light, into an electronic sign. They are utilized as a part of numerous modern and buyer applications, for instance: Lamps that turn on naturally because of dimness. Position sensors that enact when an article interferes with a light bar. Optical sensors have numerous applications in R&D, national safeguard and business markets, for example, medicinal diagnostics and procedure control. But since of the expansiveness of utilizations for optical sensors, the difficulties to the configuration and working of an optical sensor for a specific application requires information of optical, material, and ecological properties that influence sensor execution. SENSORS addresses all parts of optical sensors from source and identification advances, sensor arrangements, and preparing ways to deal with applications. These optical sensors range from smaller scale tests to expansive gadgets utilized for standoff observing of modern and ecological species.

The exertion of nanostructure substance for optoelectronic gadgets, including light-discharging diodes, laser diodes, photodetectors, and photovoltaics, has pulled in significant consideration as of late because of their novel geometry. Nanostructures in little measurements can be superbly coordinated into an assortment of mechanical stages, offering novel physical and synthetic properties for the elite optoelectronic gadgets. The misuse of new nanostructures and their optical and electrical properties is fundamental for their rising down to earth gadget applications.

Optical sensors have significant applications crosswise over different segments, for example, business, resistance, medicinal gear, and innovative work. Expanding sending of optical sensors over the aforementioned portions is required to fuel the interest for optical frameworks at the worldwide level. There are different favorable circumstances of optical sensors for these applications including more prominent affectability, electrical lack of involvement, opportunity from electromagnetic obstruction, wide element range, both point and disseminated design, and multiplexing capacities. Inferable from these elements, the optical sensor business sector was considered by BCC Research to be a critical zone for study.