Recently, strongly modulated photonic crystals, fabricated by the state-of-the-art semiconductor nanofabrication process, have realized various novel optical properties. This paper describes the way in which they differ from other optical media, and clarifies what they can do. In particular, three important issues are considered: light confinement, frequency dispersion and spatial dispersion. First, I describe the latest status and impact of ultra-strong light confinement in a wavelength-cubic volume achieved in photonic crystals. Second, the extreme reduction in the speed of light is reported, which was achieved as a result of frequency dispersion management. Third, strange negative refraction in photonic crystals is introduced, which results from their unique spatial dispersion, and it is clarified how this leads to perfect imaging. The last two sections are devoted to applications of these novel properties. First, I report the fact that strong light confinement and huge light–matter interaction enhancement make strongly modulated photonic crystals promising for on-chip all-optical processing, and present several examples including all-optical switches/memories and optical logics. As a second application, it is shown that the strong light confinement and slow light in strongly modulated photonic crystals enable the adiabatic tuning of light, which leads to various novel ways of controlling light, such as adiabatic frequency conversion, efficient optomechanics systems, photon memories and photons pinning.

https://iopscience.iop.org/article/10.1088/0034-4885/73/9/096501/pdf

Manipulating light with strongly modulated photonic crystals

Recent developments in silicon based optoelectronics relevant to fiber optical communication are reviewed. Silicon-on-insulator photonic integrated circuits represent a powerful platform that is truly compatible with standard CMOS processing. Progress in epitaxial growth of silicon alloys has created the potential for silicon based devices with tailored optical response in the near infrared. The deep submicrometer CMOS process can produce gigabits-per-second low-noise lightwave electronics. These trends combined with economical incentives will ensure that silicon-based optoelectronics will be a player in future fiber optical networks and systems.

Advances in silicon-on-insulator optoelectronics

The techniques for fabrication and the properties of periodic and aperiodic fibre Bragg gratings produced by UV exposure in photosensitive optical fibres are reviwwed with an emphasis on applications.

Uv-written in-fibre Bragg gratings

We propose a transmission-based dispersion compensator employing an apodized, unchirped fiber Bragg grating (FBG). A theoretical model for dispersion compensation in transmission based on the dispersive properties of the periodic structure is developed. A figure of merit is defined for optimization of the grating parameters for maximum recompression of dispersion-broadened optical pulses in long-haul communication systems. Numerical examples confirm that nearly perfect compensation with very low insertion losses can be achieved for many practical cases of interest.

Fiber Bragg gratings for dispersion compensation in transmission: theoretical model and design criteria for nearly ideal pulse recompression

A single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber (EDF) laser based on a simple linear cavity is proposed and demonstrated. The SLM operation is achieved by incorporating a dual-phase-shift fiber grating with two ultranarrow transmission bands. Due to the gain grating produced by spatial hole-burning in the EDF, the proposed linear cavity supports dual-wavelength oscillation at room temperature with a wavelength interval of 27 pm. The laser output is heterodyned on a photodetector and the generated microwave signal has a linewidth <20 kHz without any feedback.

Dual-wavelength erbium-doped fiber laser with a simple linear cavity and its application in microwave generation

It is shown that the transmission spectrum of a fiber Bragg grating can be tailored by incorporating single or multiple phase-shift regions during the fabrication process. Phase shifts open up narrowband transmission windows inside the stop band of the Bragg grating; transmitted wavelength can be changed by adjusting the amount of phase shift. As a specific application, we discuss how phase-shifted Bragg gratings can be used to make an all-fiber demultiplexer for multichannel lightwave systems. >

S. Radic

Papers

Phase-shifted fiber Bragg gratings and their application for wavelength demultiplexing