11-02-2013, 10:54 AM
Photonic crystal fiber uses devices
[attachment=50446]
ABSTRACT:
This paper introduces photonic crystal fiber uses devices. The modern instruments and techniques are costly as well as out of reach from rural areas. Photonic crystal fiber is now finding applications in fiber optic communications, fiber lasers, nonlinear devices, high power transmission ,highly sensitive gas sensors.
INTRODUCTION:
Photonic crystal:- Photonic crystals are periodic optical nanostructures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons. Photonic crystals occur in nature and in various forms have been studied scientifically for the last 100 years. Photonic crystals are composed of periodic dielectric or mettalo-dielectric nanostructures that affect the propagation of electromagnetic waves (EM) in the same way as the periodic potential in a semiconductor crystal affects the electron motion by defining allowed and forbidden electronic energy bands.
Applications:
Photonic crystals are attractive optical materials for controlling and manipulating the flow of light. One dimensional photonic crystal are already in widespread use in the form of thin-film optics with applications ranging from low and high reflection coatings on lenses and mirrors to colour changing paints and inks. Higher dimensional photonic crystals are of great interest for both fundamental and applied research, and the two dimensional ones are beginning to find commercial applications. The first commercial products involving two-dimensionally periodic photonic crystals are already available in the form of photonic-crystal fibers.
Construction:
Generally, such fibers are constructed by the same methods as other optical fibers: first, one constructs a "preform" on the scale of centimeters in size, and then heats the preform and draws it down to a much smaller diameter (often nearly as small as a human hair), shrinking the preform cross section but (usually) maintaining the same features. In this way, kilometers of fiber can be produced from a single preform.
APPLICATION OF THE ARROW CONCEPT IN PHOTONIC CRYSTAL WAVEGUIDES:
The thickness of the first silicon cladding beneath the silica core is deliberately chosen to provide high reflectance by the interference principle, like a Fabry-Perot resonator, which have broad reflecting windows on antiresonant wavelengths and sharp transmission peaks on resonant wavelengths. In order to enhance the resonance effect the silicon cladding is underpinned by a second cladding layer made from silica. The condition for resonant reflection of the evanescent fields penetrating through the first cladding is fulfilled by making the thickness of the silicon cladding approximately half that of the silica core. Thus, in total, a reflection around 99.96% at the bottom interface of the core arises. Under the zero-order approximation, the claddings are nothing else but λ/4 plates with respect to the transverse component of the wave-vector.
CONCLUSIONS:
I have addressed an anti-resonant reflection wave-guiding platform to be employed within PCW designs. A strong resonance dependence of the transmission spectrum is clearly seen. Structures with a lowered core index have larger losses .we also checked the roll of photonic crystal fiber in high power laser. I also describe the Fiber laser concepts and Commercial holey fiber laser.
[attachment=50446]
ABSTRACT:
This paper introduces photonic crystal fiber uses devices. The modern instruments and techniques are costly as well as out of reach from rural areas. Photonic crystal fiber is now finding applications in fiber optic communications, fiber lasers, nonlinear devices, high power transmission ,highly sensitive gas sensors.
INTRODUCTION:
Photonic crystal:- Photonic crystals are periodic optical nanostructures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons. Photonic crystals occur in nature and in various forms have been studied scientifically for the last 100 years. Photonic crystals are composed of periodic dielectric or mettalo-dielectric nanostructures that affect the propagation of electromagnetic waves (EM) in the same way as the periodic potential in a semiconductor crystal affects the electron motion by defining allowed and forbidden electronic energy bands.
Applications:
Photonic crystals are attractive optical materials for controlling and manipulating the flow of light. One dimensional photonic crystal are already in widespread use in the form of thin-film optics with applications ranging from low and high reflection coatings on lenses and mirrors to colour changing paints and inks. Higher dimensional photonic crystals are of great interest for both fundamental and applied research, and the two dimensional ones are beginning to find commercial applications. The first commercial products involving two-dimensionally periodic photonic crystals are already available in the form of photonic-crystal fibers.
Construction:
Generally, such fibers are constructed by the same methods as other optical fibers: first, one constructs a "preform" on the scale of centimeters in size, and then heats the preform and draws it down to a much smaller diameter (often nearly as small as a human hair), shrinking the preform cross section but (usually) maintaining the same features. In this way, kilometers of fiber can be produced from a single preform.
APPLICATION OF THE ARROW CONCEPT IN PHOTONIC CRYSTAL WAVEGUIDES:
The thickness of the first silicon cladding beneath the silica core is deliberately chosen to provide high reflectance by the interference principle, like a Fabry-Perot resonator, which have broad reflecting windows on antiresonant wavelengths and sharp transmission peaks on resonant wavelengths. In order to enhance the resonance effect the silicon cladding is underpinned by a second cladding layer made from silica. The condition for resonant reflection of the evanescent fields penetrating through the first cladding is fulfilled by making the thickness of the silicon cladding approximately half that of the silica core. Thus, in total, a reflection around 99.96% at the bottom interface of the core arises. Under the zero-order approximation, the claddings are nothing else but λ/4 plates with respect to the transverse component of the wave-vector.
CONCLUSIONS:
I have addressed an anti-resonant reflection wave-guiding platform to be employed within PCW designs. A strong resonance dependence of the transmission spectrum is clearly seen. Structures with a lowered core index have larger losses .we also checked the roll of photonic crystal fiber in high power laser. I also describe the Fiber laser concepts and Commercial holey fiber laser.