scholarly journals Amplitude electro-optical modulation of radiation by sequences of Fabry-Perot resonators

Author(s):  
V. B. Zalesski ◽  
A. I. Konoiko ◽  
V. M. Kravchenko ◽  
H. S. Kuzmitskaya

In this paper, we considered the method of amplitude electro-optical modulation of radiation using sequences of Fabry-Perot resonators based on the transverse electro-optical effect on the example of lithium niobate LiNbO3. With this method, it is possible to significantly reduce the voltage of the control electromagnetic field of the electro-optical amplitude modulator operating in the transmission mode of the light beam while maintaining its high efficiency. The reduction of the control voltage is achieved by increasing the number of Fabry-Perot resonators installed in series and the phase shift relative to the extremum of the transmittance function. This method allows to diminish the duration of the received light signals which leads to an increase in the clock frequency while maintaining a high efficiency of the radiation modulation. Diminishing the duration of light signals is achieved by using separate modulation channels of two sequences of electro-optical Fabry-Perot resonators, the first of which works on the transmission and the second one on the reflection. Increasing the clock frequency at the output of the modulator is achieved by summing the signals coming from several modulation channels. It is shown that the value of the control voltage for an amplitude electro-optical modulator based on a sequence of Fabry-Perot resonators made of lithium niobate LiNbO3, with an operating wavelength of 1.307 microns, can be 4 V in the case when its initial operating point corresponds to the maximum transmittance. The control voltage is 2 V if the initial operating point is shifted in phase relative to the extremum of the transmittance function.


Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 117
Author(s):  
Yu-Kai Chen ◽  
Hong-Wen Hsu ◽  
Chau-Chung Song ◽  
Yu-Syun Chen

This paper proposes the design and implementation of inductor-inductor-capacitor (LLC) converters with modules connected in series with the power scan method and communication scan network (CSN) to achieve MPPT and regulate the output voltage for the PV micro-grid system. The Dc/Dc converters includes six isolated LLC modules in series to supply ±380 V output voltage and track the maximum power point of the PV system. The series LLC converters are adopted to achieve high efficiency and high flexibility for the PV micro-grid system. The proposed global maximum power scan technique is implemented to achieve global maximum power tracking by adjusting the switching frequency of the LLC converter. To improve the system flexibility and achieve system redundancy, module failure can be detected in real time with a communication scan network, and then the output voltage of other modules will be changed by adjusting the switching frequency to maintain the same voltage as before the failure. Additionally, the proposed communication scan network includes the RS-485 interface of the MPPT series module and the CAN BUS communication interface with other subsystems’ communication for the PV micro-grid application system. Finally, a 6 kW MPPT prototype with a communication scan network is implemented and the proposed control method is verified for the PV system.



2020 ◽  
Vol 2020 (6) ◽  
pp. 25-31
Author(s):  
K.O. Lypkivskyi ◽  
◽  
A.G. Mozharovskyi ◽  

One of the effective ways to ensure the normalized operation of the electricity consumer with an unstable primary power source is the organization of the corresponding voltage supply channel. In a system with a direct current source, the voltage supply is implemented by introducing a rectifier semiconductor bridge in series with the load, into the diagonal of which AC energy is supplied, the voltage level of which is purposefully changed by a corresponding converter with a transformer- and-switches executive structure (TSES). To achieve high efficiency of the use of key elements of TSVS, it is proposed to assign the functions of rectification and voltage regulation to a specific class of TSES – a multilevel rectifier consisting of a transformer and a finite set of parallel connected pairs of serially connected thyristors, the common points of which are connected to the corresponding taps of the sectioned secondary turns of the transformer. By discrete-time control of thyristors, it is necessary to regulate voltage levels, it is attached. The linearity of the scale of these levels is ensured by the proposed transformer sectioning law. This power supply system is characterized by small energy losses in semiconductor elements (only two thyristors work at a time), and the a priori impossibility of emergency situations during transitions from one level to another. References 14, figures 3, tables 3.



Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Feiying Sun ◽  
Changbin Nie ◽  
Xingzhan Wei ◽  
Hu Mao ◽  
Yupeng Zhang ◽  
...  

Abstract Two-dimensional (2D) materials with excellent optical properties and complementary metal-oxide-semiconductor (CMOS) compatibility have promising application prospects for developing highly efficient, small-scale all-optical modulators. However, due to the weak nonlinear light-material interaction, high power density and large contact area are usually required, resulting in low light modulation efficiency. In addition, the use of such large-band-gap materials limits the modulation wavelength. In this study, we propose an all-optical modulator integrated Si waveguide and single-layer MoS2 with a plasmonic nanoslit, wherein modulation and signal light beams are converted into plasmon through nanoslit confinement and together are strongly coupled to 2D MoS2. This enables MoS2 to absorb signal light with photon energies less than the bandgap, thereby achieving high-efficiency amplitude modulation at 1550 nm. As a result, the modulation efficiency of the device is up to 0.41 dB μm−1, and the effective size is only 9.7 µm. Compared with other 2D material-based all-optical modulators, this fabricated device exhibits excellent light modulation efficiency with a micron-level size, which is potential in small-scale optical modulators and chip-integration applications. Moreover, the MoS2-plasmonic nanoslit modulator also provides an opportunity for TMDs in the application of infrared optoelectronics.



Author(s):  
Sanjay Kumar ◽  
Ghanshyam Singh ◽  
Vijay Janyani ◽  
Oleh Buryy ◽  
Ubizskii Serhij ◽  
...  






Author(s):  
Maria V. Kotlyar ◽  
Simone Iadanza ◽  
Liam O’Faolain
Keyword(s):  


2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Yueqiang Hu ◽  
Xuhao Luo ◽  
Yiqin Chen ◽  
Qing Liu ◽  
Xin Li ◽  
...  

Abstract Metasurfaces enable the design of optical elements by engineering the wavefront of light at the subwavelength scale. Due to their ultrathin and compact characteristics, metasurfaces possess great potential to integrate multiple functions in optoelectronic systems for optical device miniaturisation. However, current research based on multiplexing in the 2D plane has not fully utilised the capabilities of metasurfaces for multi-tasking applications. Here, we demonstrate a 3D-integrated metasurface device by stacking a hologram metasurface on a monolithic Fabry–Pérot cavity-based colour filter microarray to simultaneously achieve low-crosstalk, polarisation-independent, high-efficiency, full-colour holography, and microprint. The dual functions of the device outline a novel scheme for data recording, security encryption, colour displays, and information processing. Our 3D integration concept can be extended to achieve multi-tasking flat optical systems by including a variety of functional metasurface layers, such as polarizers, metalenses, and others.



We report the first observations of bifurcation routes to chaos in an all-optical resonator. Generation of associated deep and sustained Ikeda oscillation of the smooth CO 2 laser input pulses at twice the round-trip time of the Fabry-Perot resonator provides a high-frequency ( ca .0.1 GHz) passive optical modulator device. Results are in excellent agreement with our adaption of optical bistability theory to the time-dependent regime



Sign in / Sign up

Export Citation Format

Share Document