scholarly journals Spontaneous Polarization Reversal Induced by Proton Exchange in Z-Cut Lithium Niobate α-Phase Channel Waveguides

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7127
Author(s):  
Alicia Petronela Rambu ◽  
Vasile Tiron ◽  
Eugen Oniciuc ◽  
Sorin Tascu

The α-phase waveguides directly produced in one fabrication step only are well known for preserving both the excellent nonlinear properties and the ferroelectric domains orientation of lithium niobate substrates. However, by using the piezoresponse force microscopy (PFM), we present a coherent study on ferroelectric dipoles switching induced by the fabrication process of α-phase waveguides on Z-cut congruent lithium niobate (CLN) substrates. The obtained results show that the proton exchange process induces a spontaneous polarization reversal and a reduction in the piezoelectric coefficient d33. The quantitative assessments of the impact of proton exchange on the piezoelectric coefficient d33 have been quantified for different fabrication parameters. By coupling systematic PFM investigation and optical characterizations of α-phase protonated regions and virgin CLN on ±Z surfaces of the samples, we find a very good agreement between index contrast (optical investigation) and d33 reduction (PFM investigations). We clearly show that the increase in the in-diffused proton concentration (increase in index contrast) in protonated zones decreases the piezoelectric coefficient d33 values. Furthermore, having a high interest in nonlinear performances of photonics devices based on PPLN substrates, we have also investigated how deep the spontaneous polarization reversal induced by proton exchange takes place inside the α-phase channel waveguides.

2005 ◽  
Vol 480-481 ◽  
pp. 429-436
Author(s):  
M. Domenech ◽  
G. Lifante ◽  
F. Cussó ◽  
A. Parisi ◽  
A.C. Cino ◽  
...  

In this work, the complete fabrication process which combines Proton Exchange (PE) and Reverse Proton Exchange (RPE) in Neodymium doped LiNbO3 channel waveguides is reported. To produce the PE-RPE channel waveguides the fabrication of dielectric SiO2 masks had to be implemented. For this propose, we adopted a technique based on the Ion Plating Plasma Assisted Deposition of SiO2 followed by the standard ultraviolet photolithographic patterning. On the other hand, we determined the main optical and spectroscopic properties of Nd3+ ions in the channel waveguides including the study of the lifetime as function as the polarisation.


2010 ◽  
Vol 09 (04) ◽  
pp. 311-315
Author(s):  
G. Y. SI ◽  
A. J. DANNER ◽  
J. H. TENG ◽  
S. S. ANG ◽  
A. B. CHEW ◽  
...  

Channel waveguides have been fabricated in x-cut lithium niobate (LiNbO3) by proton exchange (PE) method and optically measured. The thickness and the optical constants of the thin PE layer were characterized using a prism coupling technique. The PE area was plasma etched and a 2.775-μm total etching depth was achieved. The measured average etching rate is 92.5 nm/min. One- and two-dimensional dense arrays of LiNbO3 nanostructures have also been fabricated by using interference lithography (IL) and inductively coupled plasma reactive ion etching (ICP-RIE) techniques.


2021 ◽  
Vol 11 (21) ◽  
pp. 9853
Author(s):  
Roman Ponomarev ◽  
Yuri Konstantinov ◽  
Maxim Belokrylov ◽  
Ivan Lobach ◽  
Denis Shevtsov

This work is devoted to the study of the pyroelectric effect on the properties of optical waveguides formed in a lithium niobate crystal by proton exchange. In the present work, we studied the cessation effect of the radiation channeling during thermocycling of Y-splitters samples. We examined the spectral dependence of optical losses on the wavelength using an optical spectrum analyzer. The results demonstrate that in the range of 1530–1570 nm, all wavelengths are suppressed equally. The optical frequency domain reflectometry shows that the increase of optical losses is observed along the entire waveguide, but not only at the Y-splitting point, as supposed earlier.


2019 ◽  
Vol 9 (21) ◽  
pp. 4585
Author(s):  
Roman Sergeevitch Ponomarev ◽  
Denis Igorevitch Shevtsov ◽  
Pavel Victorovitch Karnaushkin

It is shown that the termination of the channeling of the fundamental radiation mode in the waveguide can be observed upon heating of an optical integrated circuit based on proton exchange channel waveguides formed in a lithium niobate single crystal. This process is reversible, but restoration of waveguide performance takes tens of minutes. The effect of the waveguide disappearance is observed upon rapid heating (5 K/min) from a low temperature (minus 40 °C). This effect can lead to a temporary failure of navigation systems using fiber optic gyroscopes with modulators based on a lithium niobate crystal.


Author(s):  
Roman Ponomarev ◽  
Yuri Konstantinov ◽  
Ivan Lobach ◽  
Maxim Belokrylov ◽  
Denis Shevtsov

This work is devoted to the study of the pyroelectric effect on the qualities of optical waveguides formed in a lithium niobate crystal by proton exchange. In the present work, we investigated the cessation effect of the radiation channeling during thermocycling of Y-splitters samples. We examined the spectral dependence of optical losses on a wavelength using an optical spectrum analyzer. The results demonstrate that in the range of 1530–1570 nm, all wavelengths are suppressed equally. The optical reflectometry method in the frequency domain shows that the increase of optical losses is observed along the entire waveguide, but not only at the Y-distribution point, as supposed earlier.


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