@mastersthesis {10001,
	title = {Adaptive optics for fast optical communication: Spatial solutions for spectral issues},
	year = {2013},
	type = {PhD thesis},
	abstract = {In recent decades, the use of fast optical signals has become increasingly dominant,\&nbsp;both in scientific research and in engineering applications. High speed photonics\&nbsp;serves as the core of modern worldwide communication networks, as well as in many\&nbsp;optical signal processing applications. Such applications rely on the ability to control,\&nbsp;filter and manipulate large bandwidth signals. Traditionally, such control can be\&nbsp;realized using fast electronics. However, continuous growth in data rates makes this\&nbsp;option impractical, since the signals become too fast to control even for cutting edge\&nbsp;electric circuit technology. The alternative is to use an all-optical system, where signal\&nbsp;control is done in the frequency (spectral) domain. Such a system must be capable of\&nbsp;manipulating large bandwidth signals with high spectral resolution. Such optical\&nbsp;systems are essential in optical communication networks, for performing signal\&nbsp;conditioning, impairment mitigation and WDM channel power equalization.
In this work I explore a family of optical sub-systems combining guided-wave and\&nbsp;free-space optics for spectrally resolving optical signals at unprecedented resolution,\&nbsp;and actively manipulating the spectral components with spatial light modulator (SLM)\&nbsp;technology. The ability to combine the employed cutting edge technologies, including\&nbsp;a high resolution planar lightwave circuit (PLC) arrayed waveguide grating (AWG),\&nbsp;together with the state-of-the-art phase SLM, which was adapted from the light\&nbsp;projection industry, enables the design and demonstration of high resolution photonic\&nbsp;spectral processors (PSP). This system is capable of applying arbitrary spectral phase\&nbsp;and amplitude at high spectral resolution to an optical signal and of controlling its\&nbsp;properties in the time domain. A PSP can be configured for addressing the entire\&nbsp;conventional optical communication band, at a price of poor resolution due to the\&nbsp;finite space-bandwidth trade-off. Alternatively, the PSP can be designed as a colorless\&nbsp;adaptive device, operating with a free spectral range (FSR) matching the channel plan,\&nbsp;e.g. with a 100-GHz FSR, for in-band high-resolution wavelength division\&nbsp;multiplexing (WDM) filtering applications. By using two-dimensional free-space\&nbsp;optics achieved by crossing the PLC AWG with a bulk grating, a new broadband\&nbsp;processor was introduced. This PSP is capable of controlling independent WDM\&nbsp;channels on the 100 GHz grid at the high resolution of the colourless solution, thereby\&nbsp;shattering the space-bandwidth limitation.
Based on these concepts, a family of novel systems and implementations were\&nbsp;developed and investigated. In this thesis I introduce six papers which demonstrate the\&nbsp;design and implementation of three PSP systems, based on hybrid waveguide/free\&nbsp;space optics arrangements. The papers are divided into two groups: in the first group,\&nbsp;three papers present the evolution of the spectral processing device, from the simplest\&nbsp;version of colorless PSP up to two dimensional PSP arrangement with full spectral,\&nbsp;control along the c-band. The second group contains three papers describing several\&nbsp;implementations of these technologies, including amplitude filtering applications\&nbsp;(Nyquist-WDM generation), phase filtering applications (tunable chromatic\&nbsp;dispersion compensation and group delay stairs generation) and a demonstration of a\&nbsp;new fiber laser which was built using the PSP platform. These high spectral resolution\&nbsp;devices and systems can serve as an important element in controlling dispersion,\&nbsp;enhancing signal quality and optimally filtering a distorted signal, and their\&nbsp;development is essential for the progress in the optical fiber communication world.},
	url = {http://hufind.huji.ac.il/Record/HUJ001926166},
	author = {David Sinefeld}
}
