HAPTIC TECHNOLOGY

2/14/20161 TECHNICAL SEMINAR ONFIBRE BRAGG GRATINGS

Submitted byYADAV DANKUMAR

Under the guidance of Prof. YOGESH PARMAR

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INTRODUCTION22/14/2016Fibre grating is made by periodically changing the refraction index in the glass core of the fiber.The refraction changes are made by exposing the fiber to the UV-light with a fixed pattern.

Fig : Diagram of FBG

Working2/14/20163

Fig: working of FBG

History Of FBG

2/14/2016First fibre grating: Hill ,1978 at CRC First holographically written Bragg grating:Meltz, 1989.First devices era 1990-1996: Kashyap,Russell,Reekje,Malo,Poumellec;Ar ion 244nm. Albert ,Dyer,Herman,excimer 1980.

Types of fiber bragg gratingsDue to the change in the induced index change there are several types of grating: 1 Uniform grating. 2 Apodized grating. 3 Chirped grating2/14/20165

UNIFORM FBG APODIZED FBG

1.Here the grating is 1.the refractive index of the uniform throughout grating approaches to the core.Zero at the end of grating.2 this is simplest 2 there is variation type of of induced refractive Bragg grating. Index change.62/14/2016

Grating Waveforms

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82/14/2016There are mainly two methods of fabrication: 1. Transverse Holographic Method. 2. Phase Mask Method.FABRICATION OF FBG

TRANSVERSE HOLOGRAPHIC METHOD2/14/20169

Fig : Transverse holographic method

102/14/2016APPLICATION OF FBG Telecommunication-Filters. Wavelength Division Multiplexing (WDM) systems. Pump laser. Gain flattening filters. Highly selective filters . Chromatic dispersion compensators .

FABRY-PEROT FILTERIt consists of two FBGs with a cavity between them. It passes only particular frequencies for which the cavity is at resonance. The spacing between these frequencies is called as free spectral range. The bandwidth of the filter depends on the reflectivity.2/14/201611

122/14/2016FABRY PEROT FILTER

132/14/2016ADVANTAGES OF FP FILTER Bandwidth above 100MHz.Easy to manufacture. Low insertion loss.

APPLICATION SECTORS OF FBGFIG : sectors of FBG14

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ADVANTAGES OF FGB152/14/2016Flexibility. Low insertion loss. Low cost. Low transmission loss. Electrically inert. Peak reflectivity in OFBG can BE AS HIGH 99%.

DEVOLOPING APPLICATIONS162/14/2016 Aerospace Applications. Bragg Grating Sensors in Marine Applications. Civil Engineering Structural Monitoring. Distributed strain sensors , small , robust. Medical Applications. Nuclear Power Industry. Power Transmission Lines.

CONCLUSION172/14/2016 FBGs have revolutionized the communication industry by providing high performance, more reliable telecommunication links. They reflect a very narrow band of frequency, but can be designed to have more complex responses. They can sense parameters which vary the pitch or refractive index of grating.

REFRENCES Wei-Chong Du, Xiao-Ming Tao and HWa Yaw Tam: Fiber Bragg Grating cavity sensor, IEEE nics technology letters,vol.11,no.1,January 2013. Turan Erdogan: Fiber Grating Spectra, Journal of lightwavetechnology,vol.15,no.8,August 2012. Kenneth O. Hill, Gerald Meltz: Fiber bragg grating technology fundamentals and over view, Journal of light wave, vol.18,no.5,August 2011.2/14/201618

192/14/2016Thank You