25 research outputs found
Broadband wavelength conversion at 40Gb/s using long serpentine As2S3 planar waveguides
We demonstrate broadband wavelength conversion of a 40 Gb/s
return-to-zero signal by cross-phase modulation in a newly developed
chalcogenide glass waveguide based photonic chip. These new serpentine
As2S3 waveguides offer a nonlinear coefficient ≈1700 W-1km-1 with 5×
lower propagation loss over a length of 22.5 cm which ensures the full
propagation length contributes towards the nonlinear process. This reduces
the peak operating power thereby allowing a ×4 increase in the data rate
compared with previous results. Spectral measurements show the device
operates over a span of 40 nm while system measurements show just over 1
dB of power penalty at a bit-error rate of 10-9. This is primarily due to the
compact planar waveguide design which minimizes the effect of groupvelocity
dispersion
Long, low loss etched As2S3 chalcogenide waveguides for all-optical signal regeneration
We report on the fabrication and optical properties of etched
highly nonlinear As2S3 chalcogenide planar rib waveguides with lengths up
to 22.5 cm and optical losses as low as 0.05 dB/cm at 1550 nm - the lowest
ever reported. We demonstrate strong spectral broadening of 1.2 ps pulses,
in good agreement with simulations, and find that the ratio of nonlinearity
and dispersion linearizes the pulse chirp, reducing the spectral oscillations
caused by self-phase modulation alone. When combined with a spectrally
offset band-pass filter, this gives rise to a nonlinear transfer function
suitable for all-optical regeneration of high data rate signals
All optical wavelength conversion via cross phase modulation in chalcogenide glass rib waveguides
We demonstrate all-optical wavelength conversion in a 5 cm
As2S3 chalcogenide glass rib waveguide with 5.4 ps pulses over a
wavelength range of 10 nm near 1550 nm. We present frequency resolved
optical gating (FROG) measurements that show good converted pulse
integrity in terms of amplitude and phase in the frequency and time
domains. The short interaction length ensures that dispersion induced walkoff
does not hinder the conversion range of the device
Higher order mode conversion via focused ion beam milled Bragg gratings in Silicon-on-Insulator waveguides
We report the first Bragg gratings fabricated by Focused Ion
Beam milling in optical waveguides. We observe striking features in the
optical transmission spectra of surface relief gratings in silicon-on-insulator
waveguides and achieve good agreement with theoretical results obtained
using a novel adaptation of the beam propagation method and coupled mode
theory. We demonstrate that leaky Higher Order Modes (HOM), often
present in large numbers (although normally not observed) even in
nominally single mode rib waveguides, can dramatically affect the Bragg
grating optical transmission spectra. We investigate the dependence of the
grating spectrum on grating dimensions and etch depth, and show that our
results have significant implications for designing narrow spectral width
gratings in high index waveguides, either for minimizing HOM effects for
conventional WDM filters, or potentially for designing devices to capitalize
on very efficient HOM conversion
Ultrafast all-optical chalcogenide glass photonic circuits
Chalcogenide glasses offer large ultrafast third-order
nonlinearities, low two-photon absorption and the absence of free carrier
absorption in a photosensitive medium. This unique combination of
properties is nearly ideal for all-optical signal processing devices. In this
paper we review the key properties of these materials, outline progress in
the field and focus on several recent highlights: high quality gratings, signal
regeneration, pulse compression and wavelength conversion
High-performance Bragg gratings in chalcogenide rib waveguides written with a modified Sagnac interferometer
This paper was published in Journal of the Optical Society of America B-Optical Physics and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/abstract.cfm?URI=josab-23-7-1323. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.Mehrdad Shokooh-Saremi, Vahid G. Ta'eed, Neil J. Baker, Ian C. M. Littler, David J. Moss, Benjamin J. Eggleton, Yinlan Ruan, and Barry Luther-Davie
Chalcogenide glass advanced for all-optical processing
By the 1990s, the only way to expand the band width of optical systems was to increase the capacity of transmission systems. But the introduction of wavelength multiplexing (WDM), researchers begun to look into processing signals optically. Thereby, mor
All-Optical Wavelength Conversion of 80 Gb/s Signal in Highly Nonlinear Serpentine Chalcogenide Planar Waveguides
Newly developed 22 cm long, serpentine shaped AS2S3 waveguide exhibiting record low loss of 0.05 dB/cm and ultra-high nonlinearity of 1700 W-1km-1 enables all-optical wavelength conversion of an 80 Gb/s return-to-zero signal via cross-phase modulation
Long-period gratings in chalcogenide (As 2 S 3 ) rib waveguides
Long-period gratings in highly nonlinear chalcogenide gloss (As 2S3) rib waveguides arc fabricated. A strong resonance of ∼17 dB depths and 3 dB width of ∼ 15 nm is obtained at a wavelength of 1525 nm by coupling the fundamental mode to the HE02 mod