Key Laboratory of Luminescence and Optical Information

Beijing, China

Key Laboratory of Luminescence and Optical Information

Beijing, China
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Li Z.,Beijing Jiaotong University | Li Z.,Key Laboratory of Luminescence and Optical Information | Peng J.,Beijing Jiaotong University | Peng J.,Key Laboratory of Luminescence and Optical Information | And 4 more authors.
Optics and Laser Technology | Year: 2017

In this paper we report on a compact and feasible dual-concave cavity CW Kerr-lens mode-locked self-Raman Nd:YVO4 laser. A self-starting diode-pumped picosecond Nd:YVO4 1176 nm laser is demonstrated without any additional components, where the stimulated Stokes Raman scattering and Kerr-lens-induced mode locking are operated in the same crystal. With an incident pump power of 12 W, the average output power at 1176 nm is up to 643 mW. Meanwhile, the repetition rate and the pulse width of the fundamental laser are measured to be 1.53 GHz and 8.6 ps, respectively. In addition, the yellow laser output at 588 nm is realized by frequency doubling with a LiB3O5 crystal. © 2016 Elsevier Ltd


Li Q.,Beijing Jiaotong University | Li Q.,Key Laboratory of Luminescence and Optical Information | Wang Z.,Beijing Jiaotong University | Wang Z.,Key Laboratory of Luminescence and Optical Information | And 8 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Neuromorphic engineering has a wide range of applications in the fields of machine learning, pattern recognition, adaptive control, etc. Photonics, characterized by its high speed, wide bandwidth, low power consumption and massive parallelism, is an ideal way to realize ultrafast spiking neural networks (SNNs). Synaptic plasticity is believed to be critical for learning, memory and development in neural circuits. Experimental results have shown that changes of synapse are highly dependent on the relative timing of pre- and postsynaptic spikes. Synaptic plasticity in which presynaptic spikes preceding postsynaptic spikes results in strengthening, while the opposite timing results in weakening is called antisymmetric spike-timing-dependent plasticity (STDP) learning rule. And synaptic plasticity has the opposite effect under the same conditions is called antisymmetric anti-STDP learning rule. We proposed and experimentally demonstrated an optical implementation of neural learning algorithms, which can achieve both of antisymmetric STDP and anti-STDP learning rule, based on the cross-gain modulation (XGM) within a single semiconductor optical amplifier (SOA). The weight and height of the potentitation and depression window can be controlled by adjusting the injection current of the SOA, to mimic the biological antisymmetric STDP and anti-STDP learning rule more realistically. As the injection current increases, the width of depression and potentitation window decreases and height increases, due to the decreasing of recovery time and increasing of gain under a stronger injection current. Based on the demonstrated optical STDP circuit, ultrafast learning in optical SNNs can be realized. © 2016 SPIE.


Fu P.,State Key Laboratory of Catalysis | Yang D.,State Key Laboratory of Catalysis | Zhang F.,Key Laboratory of Luminescence and Optical Information | Yu W.,State Key Laboratory of Catalysis | And 2 more authors.
Science China Chemistry | Year: 2015

We assembled a ternary blend bulk heterojunction polymer solar cell (PSCs) containing P3HT (donor) and PC61BM (acceptor) incorporated with a dihexyl-quaterthiophene (DH4T) small molecule oligomer as a third component. By optimizing the contents of DH4T, we increased the power conversion efficiency of ternary P3HT:DH4T:PC61BM PSCs to 4.17% from 3.44% of binary P3HT:PC61BM PSCs under AM 1.5 G of 100 mW/cm2 intensity. The major improvement is from the increase of the short circuit current and fill factor that is due to the increased light absorption at short wavelength, the balanced charge carrier transportation and the enhanced hole evacuation by a DH4T-enriched layer at the anode interface. In this work, we demonstrate that the efficiency of the PSCs can be enhanced by using low-bandgap conjugated polymer and its oligomer as donors and fullerene derivatives as acceptors. © 2015 Science China Press and Springer-Verlag Berlin Heidelberg


Peng J.,Beijing Jiaotong University | Peng J.,Key Laboratory of Luminescence and Optical Information | Zheng Y.,Beijing Jiaotong University | Zheng Y.,Key Laboratory of Luminescence and Optical Information | And 4 more authors.
Applied Optics | Year: 2012

Compact passively Q-switched and mode-locked Nd3+:YVO 4/Cr4+:YAG self-Raman laser with high mode-locked repetition rate was demonstrated. The picosecond first Stokes at 1176 nm was successfully obtained. At the maximum incident pump power, the average output power was 95 mW with the mode-locked pulse repetition rate of 940 MHz. Yellow laser output of 588.2 nm was also realized by the use of LiB3O 5 frequency doubling crystal. © 2012 Optical Society of America.


Peng J.Y.,Beijing Jiaotong University | Zheng Y.,Key Laboratory Of Luminescence and Optical Information | Shen J.P.,Key Laboratory Of Luminescence and Optical Information | Shi Y.X.,Key Laboratory Of Luminescence and Optical Information
Laser Physics | Year: 2013

An original diode-pumped Q-switched and mode-locked solid state Nd:GdVO4 laser is demonstrated. The laser operates with double saturable absorbers and a new coupled laser cavity. The Q-switching envelope width is compressed to be about 15 ns and the mode-locking repetition rate is as low as 90 MHz. © 2013 Astro Ltd.


Peng J.,Beijing Jiaotong University | Peng J.,Key Laboratory of Luminescence and Optical Information | Zheng Y.,Beijing Jiaotong University | Zheng Y.,Key Laboratory of Luminescence and Optical Information | And 4 more authors.
Optics Communications | Year: 2012

Passively Q-switched mode locking in a compact Nd:GdVO 4 self-Raman laser with a Cr:YAG saturable absorber was demonstrated. The picosecond first stokes at 1173 nm was successfully obtained. When the optical cavity length changed from 167 mm to 120 mm, the mode-locked pulse repetition rate increased from 0.9 GHz to 1.25 GHz. At the maximum diode pump power of 10 W and with a pulse repetition rate of 0.9 GHz, an average output power up to 105 mW has been achieved at 1173 nm. In addition, the yellow laser output at 586.5 nm was also realized by frequency doubling with an LBO crystal. © 2012 Elsevier B.V. All rights reserved.


Li Z.H.,Beijing Jiaotong University | Li Z.H.,Key Laboratory of Luminescence and Optical Information | Peng J.Y.,Beijing Jiaotong University | Peng J.Y.,Key Laboratory of Luminescence and Optical Information | And 2 more authors.
Optics and Laser Technology | Year: 2014

In this paper we report on a mode-locked self-Raman 1.17 μm Nd:GdVO 4 laser. We successfully achieved stable CW mode-locked pulse in a diode-pumped self-Raman Nd:GdVO4 laser with a novel design of cavity included a dichroic mirror used in a special way. With an incident pump power of 10 W, the average output powers was up to 103 mW at a repetition rate of 145 MHz. © 2013 Published by Elsevier Ltd.


Feng Z.-H.,Key Laboratory of Luminescence and Optical Information | Hou Y.-B.,Key Laboratory of Luminescence and Optical Information | Shi Q.-M.,Key Laboratory of Luminescence and Optical Information | Qin L.-F.,Key Laboratory of Luminescence and Optical Information | And 6 more authors.
Chinese Physics B | Year: 2010

In the process of fabrication of polymer photovoltaic (PV) devices, poly (3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) thin film, acting as an anode buffer layer, is spin-coated under the action of an electric field. The PV devices with a PEDOT:PSS layer spin-coated under the action of a static electric field exhibit improved short-circuit current density (J sc) and power conversion efficiency (PCE). The investigation of morphology shows that the appropriate intensity of the electric field can increase the roughness of the surface of the PEDOT:PSS layer, which results in improved contact between the anode and hole transport layer and thus enhances the Jsc of the devices. Chemical analysis is also provided by x-ray photoelectron spectroscopy (XPS) spectra. © 2010 Chinese Physical Society and IOP Publishing Ltd.


Li Z.H.,Beijing Jiaotong University | Li Z.H.,Key Laboratory of Luminescence and Optical Information | Peng J.Y.,Beijing Jiaotong University | Peng J.Y.,Key Laboratory of Luminescence and Optical Information | And 2 more authors.
Optik | Year: 2015

In this paper we report on a long z-shaped cavity megahertz, self-mode-locked Nd:GdVO4 laser. A diode-pumped Kerr-lens mode-locking Nd:GdVO4 laser was obtained without any additional components, which operated at the third harmonic mode locking. With an incident pump power of 8 W, the average output power was up to 2 W. And the repetition rate was 450 MHz. © 2014 Elsevier GmbH. All rights reserved.


Li Q.,Beijing Jiaotong University | Li Q.,Key Laboratory of Luminescence and Optical Information | Wang Z.,Beijing Jiaotong University | Wang Z.,Key Laboratory of Luminescence and Optical Information | And 6 more authors.
Applied Optics | Year: 2014

Blind source separation (BSS) is implemented for optical fiber sensing systems, such as the fiber Bragg grating (FBG) sensing system and the single-mode-multimode-single-mode fiber (SMS) sensing system. The FastICA, a kind of multichannel BSS algorithm, is used to get the strain and the temperature with two FBGs. For the SMS sensing, a single-channel blind source separation (SCBSS) algorithmis employed to simultaneously measure the vibration and the temperature variation with only one SMS sensor. The errors of both the FBG and the SMS optical fiber sensing system are very small with the BSS algorithm. The implementation of BSS for the optical fiber sensing makes the multiparameter measurements more easily with low cost and high accuracy and can also be applied for signal de-noising field. © 2014 Optical Society of America.

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