scholarly journals A Tunable Dual-Passband Microwave Photonic Filter Based on Optically Injected Distributed Feedback Semiconductor Lasers and Dual-Output Mach-Zehnder Modulator

2020 ◽  
Vol 10 (10) ◽  
pp. 3631
Author(s):  
Jiayi Zhao ◽  
Jingjing Hu ◽  
Pengcheng Deng ◽  
Runze Yu ◽  
Ruoxian Liu ◽  
...  
Keyword(s):  
Semiconductor Lasers ◽  
Insertion Loss ◽  
Distributed Feedback ◽  
Center Frequency ◽  
Optical Signals ◽  
Microwave Photonic ◽  
Tunable Range ◽  
Novel Approach ◽  
Mach Zehnder Modulator ◽  
High Flexibility

In this paper, a novel approach to achieving a wideband tunable dual-passband microwave photonic filter (MPF) is proposed based on optical-injected distributed feedback (DFB) semiconductor lasers and a dual-output Mach–Zehnder modulator (DOMZM). The fundamental concepts for realizing the MPF are the wavelength-selective amplification effect and the period-one oscillation state under optically injected DFB lasers. These effects provide a widely tunable range of center frequency, along with high flexibility and low insertion loss. The proposed MPF is experimentally demonstrated, showing that the dual-passband center frequency in the MPF can be tuned independently from 19 to 37 GHz by adjusting the detuning frequency and injection ratio. Meanwhile, the insertion loss of the system is about 15 dB when there is no optical or electrical amplifier in the MPF link. The out-of-band suppression ratio of the MPF is more than 20 dB, which can be improved by adjusting the power of the two optical signals.

scholarly journals Experimental investigation on a novel approach for laser surface hardening modelling

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
L. Orazi ◽  
A. Rota ◽  
B. Reggiani
Keyword(s):  
Surface Hardening ◽  
Carbon Diffusion ◽  
Industrial Applications ◽  
Laser Surface ◽  
Simplified Approach ◽  
Laser Surface Hardening ◽  
Novel Approach ◽  
Laser Treatments ◽  
High Flexibility ◽  
Short Time

AbstractLaser surface hardening is rapidly growing in industrial applications due to its high flexibility, accuracy, cleanness and energy efficiency. However, the experimental process optimization can be a tricky task due to the number of involved parameters, thus suggesting for alternative approaches such as reliable numerical simulations. Conventional laser hardening models compute the achieved hardness on the basis of microstructure predictions due to carbon diffusion during the process heat thermal cycle. Nevertheless, this approach is very time consuming and not allows to simulate real complex products during laser treatments. To overcome this limitation, a novel simplified approach for laser surface hardening modelling is presented and discussed. The basic assumption consists in neglecting the austenite homogenization due to the short time and the insufficient carbon diffusion during the heating phase of the process. In the present work, this assumption is experimentally verified through nano-hardness measurements on C45 carbon steel samples both laser and oven treated by means of atomic force microscopy (AFM) technique.

scholarly journals Sharp Skirt Dual-Mode Bandpass Filter with Overlay Plate to Control Upper Passband Edge

2019 ◽  
Vol 8 (6) ◽  
pp. 2357-2360
Keyword(s):  
Analytical Model ◽  
Insertion Loss ◽  
Return Loss ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Dual Mode ◽  
Rf Receivers ◽  
Attenuation Level ◽  
Frequency Selective ◽  
Fixed Center

This paper presents design and analytical model for Sharp Skirt Dual-Mode Bandpass Filter for RF receivers. Proposed filter is designed using open stub loaded H shaped resonator. Based on analytical model insertion loss S21 and return loss S11 for proposed filter are demonstrated. Inductive Overlaying plate is proposed to control upper passband edge of proposed filter to improve frequency selectivity with fixed center frequency. The proposed filter has sharp frequency selective range from 5.1GHz to 9.2GHz. With overlay plate, frequency selective range is tuned to 5.1GHz-8.6GHz. Without overlaying plate the proposed filter has return loss greater than 10dB and insertion loss of 0.7dB. Lower and upper passband edges are at 5.1GHz and 9.2GHz with attenuation level of 52dB and 54dB respectively. With overlaying plate, the filter has same S 11 and S 21 parameters, but upper passband edge is shifted from 9.2GHz to 8.6GHz

Purely gain‐coupled distributed feedback semiconductor lasers

1990 ◽  
Vol 56 (17) ◽  
pp. 1620-1622 ◽  
Author(s):  
Y. Luo ◽  
Y. Nakano ◽  
K. Tada ◽  
T. Inoue ◽  
H. Hosomatsu ◽  
...  
Keyword(s):  
Semiconductor Lasers ◽  
Distributed Feedback

Reconfigurable dual-mode band-pass filter with switchable bandwidth using PIN diodes

2014 ◽  
Vol 7 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Photos Vryonides ◽  
Symeon Nikolaou ◽  
Sangkil Kim ◽  
Manos M. Tentzeris
Keyword(s):  
Insertion Loss ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Dual Mode ◽  
Pin Diodes ◽  
Pass Filter ◽  
Physical Size ◽  
Wireless Applications ◽  
Band Pass ◽  
Dc Bias

A reconfigurable band-pass filter with switchable bandwidth, for wireless applications is demonstrated using a dual-mode microstrip square-loop resonator. The proposed filter has been designed on Rogers RO4003C and achieves switchable bandwidth by changing the length of two tuning stubs with the implementation of two strategically placed p-i-n diodes as switching elements. The filter was designed with a center frequency of 2.4 GHz and the two distinct operation states have bandwidths, 113 MHz (4.8%) with an insertion loss of 1.2 dB and 35 MHz (1.5%) with an insertion loss of 1.5 dB. The physical size of the fabricated reconfigurable filter including the implementation of the DC bias lines is comparable to the size of a conventional filter.

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