The University of Southampton
University of Southampton Institutional Repository

Rectangular pulse generation based on pulse reshaping using a superstructured fiber Bragg grating

Rectangular pulse generation based on pulse reshaping using a superstructured fiber Bragg grating
Rectangular pulse generation based on pulse reshaping using a superstructured fiber Bragg grating
Recent advances in ultrafast laser technology call for new all-optical methods for precisely manipulating and controlling the shape of short pulses. The most widely known pulse-shaping technique involves filtering of the spatially dispersed frequency components of a short pulse using bulk gratings and appropriate phase and amplitude masks. Alternative coherent pulse shaping techniques have also been developed. For example, in Ref [2] pulse shaping was achieved using second-harmonic generation in aperiodic quasi-phase-matching structures. The use of arrayed-waveguide gratings for optical processing applications has also been proposed. Fiber Bragg Gratings (FBGs) can also be viewed, and used, as spectral filters of controllable phase and amplitude. FBGs offer all the advantages associated with fiber components, such as ready integration into fiber systems, minimal coupling losses, and in addition offer tunability through control of the grating's strain and temperature. For a weak FBG, i.e. one in which light penetrates through the full grating, its frequency response is given by the Fourier transform of the index modulation profile along the grating length. This principle has been used in the past, in conjuction with conventional uniform FBG designs, to generate a train of dark pulses, and to obtain a matched filter for the detection of loops square pulses. However, advances in the fabrication of FBGs now allow the fabrication of gratings with almost arbitrary amplitude and phase characteristics, greatly extending the range of applications of the approach. Control of the grating's frequency response is obtained by spatially modulating a uniform grating's refractive index profile with a sampling function that corresponds to the desired impulse response of the grating. Recently, we demonstrated the use of relatively simple superstructured gratings for pattern generation and recognition, as required for optical code division multiple access applications (OCDMA), and have also demonstrated the use of an FBG to perform pulse repetition rate multiplication from 10 to 40 GHz. In this work, we have progressed the approach, and successfully demonstrated the fabrication and use of a truly complex superstructure grating designed to transform short optical pulses (2.5 ps at 10 GHz) into a corresponding train of 20 ps rectangular pulses. Such pulse forms are suited to nonlinear optical switching applications, in which a square switching window is required.
Petropoulos, P.
522b02cc-9f3f-468e-bca5-e9f58cc9cad7
Ibsen, M.
22e58138-5ce9-4bed-87e1-735c91f8f3b9
Richardson, D.J.
ebfe1ff9-d0c2-4e52-b7ae-c1b13bccdef3
Petropoulos, P.
522b02cc-9f3f-468e-bca5-e9f58cc9cad7
Ibsen, M.
22e58138-5ce9-4bed-87e1-735c91f8f3b9
Richardson, D.J.
ebfe1ff9-d0c2-4e52-b7ae-c1b13bccdef3

Petropoulos, P., Ibsen, M. and Richardson, D.J. (1999) Rectangular pulse generation based on pulse reshaping using a superstructured fiber Bragg grating. Trends in Optics and Photonics: Bragg Gratings Photosensitivity and Poling in Glass Waveguides (BGPP '99), United States. 23 - 26 Sep 1999.

Record type: Conference or Workshop Item (Paper)

Abstract

Recent advances in ultrafast laser technology call for new all-optical methods for precisely manipulating and controlling the shape of short pulses. The most widely known pulse-shaping technique involves filtering of the spatially dispersed frequency components of a short pulse using bulk gratings and appropriate phase and amplitude masks. Alternative coherent pulse shaping techniques have also been developed. For example, in Ref [2] pulse shaping was achieved using second-harmonic generation in aperiodic quasi-phase-matching structures. The use of arrayed-waveguide gratings for optical processing applications has also been proposed. Fiber Bragg Gratings (FBGs) can also be viewed, and used, as spectral filters of controllable phase and amplitude. FBGs offer all the advantages associated with fiber components, such as ready integration into fiber systems, minimal coupling losses, and in addition offer tunability through control of the grating's strain and temperature. For a weak FBG, i.e. one in which light penetrates through the full grating, its frequency response is given by the Fourier transform of the index modulation profile along the grating length. This principle has been used in the past, in conjuction with conventional uniform FBG designs, to generate a train of dark pulses, and to obtain a matched filter for the detection of loops square pulses. However, advances in the fabrication of FBGs now allow the fabrication of gratings with almost arbitrary amplitude and phase characteristics, greatly extending the range of applications of the approach. Control of the grating's frequency response is obtained by spatially modulating a uniform grating's refractive index profile with a sampling function that corresponds to the desired impulse response of the grating. Recently, we demonstrated the use of relatively simple superstructured gratings for pattern generation and recognition, as required for optical code division multiple access applications (OCDMA), and have also demonstrated the use of an FBG to perform pulse repetition rate multiplication from 10 to 40 GHz. In this work, we have progressed the approach, and successfully demonstrated the fabrication and use of a truly complex superstructure grating designed to transform short optical pulses (2.5 ps at 10 GHz) into a corresponding train of 20 ps rectangular pulses. Such pulse forms are suited to nonlinear optical switching applications, in which a square switching window is required.

Full text not available from this repository.

More information

Published date: 1999
Venue - Dates: Trends in Optics and Photonics: Bragg Gratings Photosensitivity and Poling in Glass Waveguides (BGPP '99), United States, 1999-09-23 - 1999-09-26

Identifiers

Local EPrints ID: 76504
URI: https://eprints.soton.ac.uk/id/eprint/76504
PURE UUID: f963d48b-5699-4382-8ccc-72ac17087fad
ORCID for P. Petropoulos: ORCID iD orcid.org/0000-0002-1576-8034
ORCID for D.J. Richardson: ORCID iD orcid.org/0000-0002-7751-1058

Catalogue record

Date deposited: 11 Mar 2010
Last modified: 06 Mar 2019 01:37

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×