Ultrafast, low-power, all-optical switching via birefringent phase-matched transverse mode conversion in integrated waveguides

Hellwig, Tim; Epping, Jörn P.; Schnack, Martin; Boller, Klaus-J.; Fallnich, Carsten

doi:10.1364/oe.23.019189

Cited by 10 publications

(3 citation statements)

References 25 publications

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“…Regarding third-order nonlinearities, the recent demonstration of the broadest-ever optical spectrum generated on a chip, 495 THz when pumped at 1064 nm [18], shifted more towards the mid-infrared when pumped at 1550 nm, while still maintaining a bandwidth of 453 THz [19]. This has opened a wide prospective towards four-wave mixing [20], frequency comb generation [21] and all-optical switching [22].…”

Section: Introductionmentioning

confidence: 99%

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

et al. 2017

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Abstract:We report the observation of second-harmonic generation (SHG) in stoichiometric silicon nitride waveguides grown via low-pressure chemical vapor deposition (LPCVD). Quasirectangular waveguides with a large cross section were used, with a height of 1 µm and various different widths, from 0.6 to 1.2 µm, and with various lengths from 22 to 74 mm. Using a mode-locked laser delivering 6-ps pulses at 1064 nm wavelength with a repetition rate of 20 MHz, 15% of the incoming power was coupled through the waveguide, making maximum average powers of up to 15 mW available in the waveguide depending on the waveguide cross section. Second-harmonic output was observed with a delay of minutes to several hours after the initial turn-on of pump radiation, showing a fast growth rate between 10 −4 to 10 −2 s −1 , with the shortest delay and highest growth rate at the highest input power. After this first, initial build-up (observed delay and growth), the second-harmonic became generated instantly with each new turn-on of the pump laser power. Phase matching was found to be present independent of the used waveguide width, although the latter changes the fundamental and second-harmonic phase velocities. We address the presence of a second-order nonlinearity and phase matching, involving an initial, power-dependent build-up, to the coherent photogalvanic effect. The effect, via the third-order nonlinearity and multiphoton absorption leads to a spatially patterned charge separation, which generates a spatially periodic, semi-permanent, DC-field-induced second-order susceptibility with a period that is appropriate for quasi-phase matching. The maximum measured second-harmonic conversion efficiency amounts to 0.4% in a waveguide with 0.9 × 1 µm 2 cross section and 36 mm length, corresponding to 53 µW at 532 nm with 13 mW of IR input coupled into the waveguide. The maximum equivalent χ (2) -susceptibility amounts to 3.7 pm/V, as retrieved from the measured conversion efficiency.

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Section: Introductionmentioning

confidence: 99%

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

et al. 2017

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“…4,5 The recent demonstrations of the broadest-ever optical spectrum on a chip with this specific platform, 495 Thz 6 when pumped at 1064 nm and 453 THz 7 when pumped at 1550 nm, has opened a wide prospective towards third-order nonlinear functionalities, e.g., four-wave mixing, 8 frequency comb generation 9 and the possibility of efficient all-optical switching. 10 However, a great number of additional functionalities would become possible in such a platform if a second-order susceptibility, χ (2) , would be available.…”

Section: Introductionmentioning

confidence: 99%

Photoinduced χ⁽²⁾ for second harmonic generation in stoichiometric silicon nitride waveguides

et al. 2017

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We present for the first time second harmonic generation in amorphous stoichiometric Si 3 N 4 waveguides grown via low pressure chemical vapor deposition. An effective second-order susceptibility (χ (2) ) is established via the coherent photogalvanic effect. A waveguide was designed to phase match a horizontally (parallel to the waveguide width) polarized hybrid EH 00 mode at 1064 nm with the higher-order hybrid transverse EH 02 mode at 532 nm. A mode-locked laser delivering 6.2-ps pulses at 1064 nm with a repetition rate of 20 MHz was used as pump. When pumped with a constant average power, it was found that the photoinduced χ (2) is established over a time of the order of 1000 s in as-manufactured waveguides, during which the second harmonic signal grows from below noise to a saturation value. The life-time of the photoinduced χ (2) is at least a week. In steady state, we obtain a maximum conversion efficiency close to 0.4% for an average pump power of 13 mW inside the waveguide. The effective second-order susceptibility is found to be 8.6 pm/V.

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“…In this scheme, the two optical digital input signals

P_{Bi {normalt}_{2}}

and

P_{Bi {normalt}_{1}}

represent the MSB and LSB bits power with identical magnitude. The LSB power

P_{Bi {normalt}_{1}}

is attenuated by 6 dB and added to the power of the MSB,

P_{Bi {normalt}_{2}}

after passing through a delay block that imposes a delay of T d seconds that matches the propagation delay of the attenuator block so the two input pulses are added in‐phase, the phase matching of the corresponding optical signals could be performed by other methods using a non‐linear medium [15–17]. A directional coupler is used as the optical adder.…”

Section: Binary‐weighted Pdac Architecturementioning

confidence: 99%

Binary‐weighted photonic digital‐to‐analogue converter

Abdollahi

Al-Raweshidy

Owens

2017

IET Optoelectronics

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In fifth-generation (5G) mobile networks the available bandwidth and the range of carrier frequencies will be significantly larger than in current mobile networks. To cope with the consequent increase in traffic 5G networks will be digital radio over fibre (DRoF) networks for deploying cloud radio access networks. As conventional electronic data converters in DRoF networks suffer from jitter at very high giga sampling rates while photonic data converters have better performance, photonic data converters are considered a fundamental building block of a DRoF system for 5G. All photonic DRoF (AP-DRoF) is a suitable candidate for carrying future 5G data traffic from a central station for delivery to remote pico-cells. In this study an 8-bit binary-weighted photonic digital to analogue converter (PDAC) for AP-DRoF is proposed for the conversion of an optical bit stream generated by a photonic analogue-to-digital converter into optical analogue signal for delivery to the photo diode of a remote station's photonic antenna. The potential performance of the proposed PDAC is investigated at a sampling rate of 60 Gsample/s through simulation in terms of its effective number of bits and spurious free dynamic range.

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Ultrafast, low-power, all-optical switching via birefringent phase-matched transverse mode conversion in integrated waveguides

Cited by 10 publications

References 25 publications

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

Photoinduced χ⁽²⁾ for second harmonic generation in stoichiometric silicon nitride waveguides

Binary‐weighted photonic digital‐to‐analogue converter

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Ultrafast, low-power, all-optical switching via birefringent phase-matched transverse mode conversion in integrated waveguides

Cited by 10 publications

References 25 publications

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

Photoinduced χ(2) for second harmonic generation in stoichiometric silicon nitride waveguides

Binary‐weighted photonic digital‐to‐analogue converter

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Product

Resources

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Photoinduced χ⁽²⁾ for second harmonic generation in stoichiometric silicon nitride waveguides