Discrete solitons with competing second harmonic components in lithium niobate waveguide arrays

2011 ◽  
Author(s):  
Frank Setzpfandt ◽  
Andrey A. Sukhorukov ◽  
Thomas Pertsch
Keyword(s):  
Lithium Niobate ◽  
Second Harmonic ◽  
Waveguide Arrays ◽  
Harmonic Components ◽  
Discrete Solitons

scholarly journals “Seeing Is Believing”—In-Depth Analysis by Co-Imaging of Periodically-Poled X-Cut Lithium Niobate Thin Films

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 288
Author(s):  
Sven Reitzig ◽  
Michael Rüsing ◽  
Jie Zhao ◽  
Benjamin Kirbus ◽  
Shayan Mookherjea ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Second Harmonic ◽  
Imaging Techniques ◽  
Piezoresponse Force Microscopy ◽  
Periodically Poled ◽  
Near Surface ◽  
Domain Structures ◽  
Depth Analysis ◽  
Improved Performance ◽  
Quantum Optical

Nonlinear and quantum optical devices based on periodically-poled thin film lithium niobate (PP-TFLN) have gained considerable interest lately, due to their significantly improved performance as compared to their bulk counterparts. Nevertheless, performance parameters such as conversion efficiency, minimum pump power, and spectral bandwidth strongly depend on the quality of the domain structure in these PP-TFLN samples, e.g., their homogeneity and duty cycle, as well as on the overlap and penetration depth of domains with the waveguide mode. Hence, in order to propose improved fabrication protocols, a profound quality control of domain structures is needed that allows quantifying and thoroughly analyzing these parameters. In this paper, we propose to combine a set of nanometer-to-micrometer-scale imaging techniques, i.e., piezoresponse force microscopy (PFM), second-harmonic generation (SHG), and Raman spectroscopy (RS), to access the relevant and crucial sample properties through cross-correlating these methods. Based on our findings, we designate SHG to be the best-suited standard imaging technique for this purpose, in particular when investigating the domain poling process in x-cut TFLNs. While PFM is excellently recommended for near-surface high-resolution imaging, RS provides thorough insights into stress and/or defect distributions, as associated with these domain structures. In this context, our work here indicates unexpectedly large signs for internal fields occurring in x-cut PP-TFLNs that are substantially larger as compared to previous observations in bulk LN.

scholarly journals Receptivity of Boundary Layer over a Blunt Wedge due to Freestream Pulse Disturbances at Mach 6

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jianqiang Shi ◽  
Xiaojun Tang ◽  
Zhenqing Wang ◽  
Mingfang Shi ◽  
Wei Zhao
Keyword(s):  
Boundary Layer ◽  
Fundamental Frequency ◽  
High Frequency ◽  
Pulse Wave ◽  
Second Harmonic ◽  
Acoustic Pulse ◽  
Disturbance Wave ◽  
Acoustic Disturbances ◽  
Disturbance Frequency ◽  
Harmonic Components

Direct numerical simulation (DNS) of a hypersonic compressible flow over a blunt wedge with fast acoustic disturbances in freestream is performed. The receptivity characteristics of boundary layer to freestream pulse acoustic disturbances are numerically investigated at Mach 6, and the frequency effects of freestream pulse wave on boundary layer receptivity are discussed. Results show that there are several main disturbance mode clusters in boundary layer under acoustic pulse wave, and the number of main disturbance clusters decreases along the streamwise. As disturbance wave propagates from upstream to downstream direction, the component of the modes below fundamental frequency decreases, and the component of the modes above second harmonic components increases quickly in general. There are competition and disturbance energy transfer between different boundary layer modes. The nose boundary layer is dominated by the nearby mode of fundamental frequency. The number of the main disturbance mode clusters decreases as the freestream disturbance frequency increases. The frequency range with larger growth narrows along the streamwise. In general, the amplitudes of both fundamental mode and harmonics become larger with the decreasing of freestream disturbance frequency. High frequency freestream disturbance accelerates the decay of disturbance wave in downstream boundary layer.

scholarly journals Lithium niobate particles with a tunable diameter and porosity for optical second harmonic generation

RSC Advances ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 822-833
Author(s):  
Rana Faryad Ali ◽  
Byron D. Gates
Keyword(s):  
Lithium Niobate ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Optical Second Harmonic Generation

Tunable, mesoporous lithium niobate particles with an active optical second harmonic generation (SHG) response.

Sign in / Sign up

Export Citation Format

Share Document