A Study of the Crossing Angle in Condensed-Phase CARS

A novel method of tuning the crossing angle, that is, the phase-matching condition, in condensed-phase CARS measurements has been presented. The method enables us to tune the phase-matching condition by simply tilting the sample cell with no need for adjusting the crossing angle of excitation laser beams over the range of about 600 cm−1.To this end, a relation between the crossing angle and the frequency difference between the two excitation lasers, which is associated with the Raman shift, has been derived in the normal dispersion region and has been experimentally examined.

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Crossed Two-Beam Coherent Anti-Stokes Raman Spectroscopy in Dispersive Media

Applied Spectroscopy ◽

10.1366/000370203321165269 ◽

2003 ◽

Vol 57 (1) ◽

pp. 93-99 ◽

Cited By ~ 3

Author(s):

Michael J. Papac ◽

Jonathan D. Posner ◽

Derek Dunn-Rankin

Keyword(s):

Raman Spectroscopy ◽

Gas Phase ◽

Matching Condition ◽

Laser Beams ◽

Dispersive Media ◽

Phase Matching ◽

Optical Wave ◽

Fitting Procedure ◽

Phase Matching Condition ◽

Anti Stokes

Coherent anti-Stokes Raman spectroscopy (CARS) is a nonlinear optical wave mixing process that is used in gas-phase systems to determine the energy distribution of the probed species (usually N2) and, through a fitting procedure, the temperature giving rise to it. CARS signal strengths are maximized when the phase matching condition is met. Because gases are generally non-dispersive, this phase matching condition can be found geometrically as a function of the crossing angles between the CARS beams and their wavelengths. In addition, perfect phase matching in non-dispersive media occurs automatically for collinear beams. To improve spatial resolution, however, intersecting the laser beams is desirable. Being a third-order process, phase matching for CARS in gases typically requires three input laser beams. This paper discusses and demonstrates the issues of phase matching for CARS when the medium is dispersive, and the ability for CARS phase matching to occur with only two crossed laser beams (one pump and one probe). This two-beam X-CARS in dispersive media can be used as an alignment tool for gas-phase CARS and may be relevant as a simpler diagnostic in high-pressure environments. The paper also discusses the effects of non-ideal phase matching in dispersive and non-dispersive media.

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Laser Pulse Shortening via Zero-Dispersion Phase Matching of Parametric Raman Interactions in Crystals

Crystals ◽

10.3390/cryst11010019 ◽

2020 ◽

Vol 11 (1) ◽

pp. 19

Author(s):

Sergei N. Smetanin ◽

Michal Jelínek ◽

Dmitry P. Tereshchenko ◽

Mikhail N. Ershkov ◽

Václav Kubeček

Keyword(s):

Laser Pulse ◽

Short Pulse ◽

Matching Condition ◽

Phase Matching ◽

Dispersion Phase ◽

Birefringent Crystal ◽

Raman Lasers ◽

Birefringent Crystals ◽

Phase Matching Condition ◽

Ultra Short Pulse

We propose and study the conditions of zero-dispersion phase matching for parametric Raman interactions in birefringent crystals differing by anisotropy of zero-dispersion wavelength and allowing for the spectral tuning of the zero-dispersion phase-matching condition. We choose a highly birefringent crystal of calcite having a wide zero-dispersion anisotropy range for the demonstration of new effects of laser pulse shortening in parametric Raman lasers with spectrally tunable zero-dispersion phase matching. We demonstrate the anti-Stokes (1168 nm) and multi-Stokes (1629 nm) picosecond pulse shortening and self-separation of single 80-ps ultra-short pulse from the zero-dispersion phase-matched parametric Raman lasers that are based on the calcite crystal without using any electro-optical device.

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Study on Phase Matching Condition at Pump Depletion in Four-wave Mixing

ACTA PHOTONICA SINICA ◽

10.3788/gzxb20194802.0219001 ◽

2019 ◽

Vol 48 (2) ◽

pp. 219001

Author(s):

万峰 WAN Feng ◽

武保剑 WU Bao-jian ◽

曹亚敏 CAO Ya-min ◽

邢焕兴 XING Huan-xing ◽

邱昆 QIU Kun

Keyword(s):

Matching Condition ◽

Four Wave Mixing ◽

Phase Matching ◽

Wave Mixing ◽

Phase Matching Condition ◽

Pump Depletion

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Angle-Sensitive Detector Based on Silicon-On-Insulator Photodiode Stacked with Surface Plasmon Antenna

Sensors ◽

10.3390/s20195543 ◽

2020 ◽

Vol 20 (19) ◽

pp. 5543

Author(s):

Anitharaj Nagarajan ◽

Shusuke Hara ◽

Hiroaki Satoh ◽

Aruna Priya Panchanathan ◽

Hiroshi Inokawa

Keyword(s):

Quantum Efficiency ◽

Surface Plasmon ◽

Incident Angle ◽

Matching Condition ◽

Silicon On Insulator ◽

Phase Matching ◽

Hole Array ◽

Sensitive Detector ◽

High Quantum Efficiency ◽

Phase Matching Condition

We present a pixel-level angle sensitive detector composed of silicon-on-insulator (SOI) photodiode (PD) stacked with a gold surface plasmon (SP) antenna to affect the direction of the incoming light. The surface plasmons are excited in the grating-type SP antenna and enhance the diffraction efficiency of the grating. The diffracted light is coupled strongly with the propagation light in the SOI waveguide when the phase matching condition is satisfied. The phase matching takes place at a specific angle of light incidence, and the discrimination of the light based on the incident angle is achieved. As spatial patterns in the polar coordinate of the elevation-azimuth angles (θ, ϕ) of the incident light, we present the phase matching condition theoretically, the absorption efficiency in the SOI by simulation, and also the quantum efficiency of the SOI PD experimentally for different SP antennas of one-dimensional (1D) line-and-space (L/S) and two-dimensional (2D) hole array gratings under various polarization angles. 1D grating offers a polarization sensitive angle detection and 2D grating exhibits angle detection in two orthogonal directions, enabling a polarization independent angle sensitivity. A good agreement among the theory, simulation, and experiment are attained. The proposed device features relatively high quantum efficiency as an angle-sensitive pixel (ASP) and gives wider opportunities in applications such as three-dimensional (3D) imaging, depth-of-field extension, and lensless imaging.

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Phase matching condition of THz pulse shaping in difference frequency mixing

2013 6th UK, Europe, China Millimeter Waves and THz Technology Workshop (UCMMT) ◽

10.1109/ucmmt.2013.6641528 ◽

2013 ◽

Author(s):

Dehua Li ◽

Jianjun Ma ◽

Wei Zhou ◽

Junxiang Yu ◽

Peng Zhao

Keyword(s):

Pulse Shaping ◽

Matching Condition ◽

Difference Frequency ◽

Phase Matching ◽

Phase Matching Condition ◽

Frequency Mixing

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Broadband Supercontinuum Generation in a Tapered-Rib Lead-Silicate Waveguide

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156415500093 ◽

2015 ◽

Vol 24 (03n04) ◽

pp. 1550009 ◽

Cited By ~ 2

Author(s):

Hongyu Hu ◽

Wenbo Li ◽

Xiang Zhang ◽

Niloy K. Dutta

Keyword(s):

Numerical Simulations ◽

Matching Condition ◽

Supercontinuum Generation ◽

Phase Matching ◽

Etch Depth ◽

Lead Silicate ◽

Dispersive Wave ◽

Output Spectrum ◽

Wave Emission ◽

Phase Matching Condition

We have studied supercontinuum generation in a tapered-rib lead-silicate waveguide. The Air-SF57 glass-SiO2 waveguide is 2 cm long, with a varying etch depth to manage the dispersion profile. Numerical simulations are conducted for input sech2 pulses centered at 1.55 μm. Due to continuous modification of the phase matching condition for dispersive wave emission, the proposed waveguide geometry generates broadband output spectrum extending from ~1 μm to ~4.6 μm at −30 dB level. With proper pumping conditions, fully coherent supercontinuum can be obtained.

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