scholarly journals Effective Generation of Milliwatt-Level Sub-Terahertz Wave for Nonlinear Response Measurement of Two-Dimensional Material by Optical Heterodyne Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shuqing Chen ◽  
Zhiqiang Xie ◽  
Junmin Liu ◽  
Yanliang He ◽  
Yao Cai ◽  
...  

By using optical heterodyne technique, we demonstrated the stable emission of sub-terahertz wave with the frequency ranging from 88 GHz to 101 GHz, which can operate as microwave source for nonlinear response measurement system. Mutual frequency beating of two well-separated sideband signals at a 0.1 THz photo-detector (PD) allows for the generation of sub-terahertz signal. Based on this approach, we have achieved the radiation of 0.1 THz wave with power up to 4 mW. By transmittance measurement, two-dimensional nanomaterial topological insulator (TI: Bi2Te3) shows saturable absorption behaviors with normalized modulation depth of 47% at 0.1 THz. Our results show that optical heterodyne technique could be developed as an effective microwave source generation for nonlinear measurement at sub-terahertz, even terahertz band.

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 865 ◽  
Author(s):  
Tao Wang ◽  
Jin Wang ◽  
Jian Wu ◽  
Pengfei Ma ◽  
Rongtao Su ◽  
...  

In recent years, metal chalcogenide nanomaterials have received much attention in the field of ultrafast lasers due to their unique band-gap characteristic and excellent optical properties. In this work, two-dimensional (2D) indium monosulfide (InS) nanosheets were synthesized through a modified liquid-phase exfoliation method. In addition, a film-type InS-polyvinyl alcohol (PVA) saturable absorber (SA) was prepared as an optical modulator to generate ultrashort pulses. The nonlinear properties of the InS-PVA SA were systematically investigated. The modulation depth and saturation intensity of the InS-SA were 5.7% and 6.79 MW/cm2, respectively. By employing this InS-PVA SA, a stable, passively mode-locked Yb-doped fiber laser was demonstrated. At the fundamental frequency, the laser operated at 1.02 MHz, with a pulse width of 486.7 ps, and the maximum output power was 1.91 mW. By adjusting the polarization states in the cavity, harmonic mode-locked phenomena were also observed. To our knowledge, this is the first time an ultrashort pulse output based on InS has been achieved. The experimental findings indicate that InS is a viable candidate in the field of ultrafast lasers due to its excellent saturable absorption characteristics, which thereby promotes the ultrafast optical applications of InX (X = S, Se, and Te) and expands the category of new SAs.


2012 ◽  
Vol 1437 ◽  
Author(s):  
Taiichi Otsuji ◽  
Stephane Boubanga Tombet ◽  
Akira Satou ◽  
Maxim Ryzhii ◽  
Victor Ryzhii

ABSTRACTIn this paper recent advances in terahertz-wave generation in graphene are reviewed. First, fundamental basis of the optoelectronic properties of graphene is introduced. Second, nonequilibrium carrier relaxation and recombination dynamics in optically or electrically pumped graphene is described to introduce a possibility of negative dynamic conductivity in a wide terahertz range. Third, recent theoretical advances toward the creation of current-injection graphene terahertz lasers are described. Fourth, unique terahertz dynamics of the two-dimensional plasmons in graphene are described. Finally, the advantages of graphene materials and devices for terahertz-wave generation are summarized.


1996 ◽  
Vol 05 (03) ◽  
pp. 465-476 ◽  
Author(s):  
L. LEPETIT ◽  
G. CHÉRIAUX ◽  
M. JOFFRE

We propose a new technique, using femtosecond Fourier-transform spectral interferometry, to measure the second-order nonlinear response of a material in two dimensions of frequency. We show numerically the specific and unique information obtained from such a two-dimensional measurement. The technique is demonstrated by measuring the second-order phase-matching map of two non-resonant nonlinear crystals.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2078
Author(s):  
Qianqian Shi ◽  
Guodong Zhang ◽  
Yuheng Wang ◽  
Yu Lan ◽  
Jiang Wang ◽  
...  

Vanadium pentoxide (V2O5) is the most stable phase among many transition metal vanadium oxides, and has already been widely used in many fields. In this study, the morphological, structural, and optical responses of V2O5 film to ultrafast laser irradiation was investigated. The third-order nonlinear optical properties of V2O5 film were measured by common Z-scan technique, and the results showed that V2O5 film has self-defocusing and saturable absorption characteristics. The third-order nonlinear absorption coefficient and nonlinear refractive index were calculated to be −338 cm/GW and −3.62 × 10−12 cm2/W, respectively. The tunable saturated absorption with modulation depth ranging from 13.8% to 29.3% was realized through controlling the thickness of vanadium pentoxide film. V2O5 film was irradiated by ultrafast laser with variable pulse energy, and the morphological and structural responses of the V2O5 to the laser with different energy densities were investigated. The irreversible morphological and structural responses of V2O5 films to ultrafast laser irradiation was analyzed using the phase-contrast microscope and Raman spectrum. The chemical structure change from V2O5 to V6O13 was considered the main reason for refractive index modification.


Author(s):  
Jianwei Hu ◽  
Rong Huang ◽  
Ziqiao Wei ◽  
Minru Wen ◽  
Fugen Wu ◽  
...  

Abstract Two-dimensional materials have drawn great interest for their applications in mode-locking owning to their unique optical nonlinearities. However, most of these 2D materials are semi-conductor. In this study, a new kind of semimetal Indium bismuth (InBi) is reported which is a topological nodal-line semimetal with exotic physical properties. The InBi nanomaterials was prepared through liquid phase exfoliation method with average thickness of 32.8 nm. The saturable absorption property was measured and passive mode-locking operation was achieved successfully in Er-doped fiber laser. It exhibits a modulation depth of 3.21%, a saturable intensity of 100 MW/cm2, and a pulse width about 859.97 fs corresponding to the central wavelength of 1562.27 nm and 3-dB bandwidth of 2.98 nm. The experimental results open a new avenue for the use of semimetals InBi nanomaterials in lasers and photonics applications.


2019 ◽  
Vol 52 (16) ◽  
pp. 165101 ◽  
Author(s):  
Junshan He ◽  
Yajun Lou ◽  
Yonghui Li ◽  
Yu Zhao ◽  
Mingming Hao ◽  
...  

2019 ◽  
Vol 28 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Xin Zhang ◽  
Yanli Yao ◽  
Shubin Wang ◽  
Guoli Ma ◽  
Ming Lei ◽  
...  

In this work, MoSe2 film is synthesized by the chemical vapor deposition method. Saturable absorber (SA) is assembled with the tapered fiber and MoSe2 films. Q-switched operation is achieved with the MoSe2-based SA. The experimental result reveals that the MoSe2-based SA has excellent saturable absorption characteristic with 23.41% modulation depth. When the pump power is greater than 289.2[Formula: see text]mW, Q-switched all-fiber lasing action is demonstrated. The repetition rate of the Q-switched pulses varies from 185.6 to 252.8[Formula: see text]kHz. The shortest pulse duration is 801.9[Formula: see text]ns, and the largest output energy is 69.3[Formula: see text]nJ. Results indicate that MoSe2 films can provide new opportunities for large-modulation-depth optical modulators in ultrafast photonics.


2020 ◽  
Vol 5 (4) ◽  
pp. 1901090
Author(s):  
Weien Lai ◽  
Chengda Ge ◽  
Hao Yuan ◽  
Qingfeng Dong ◽  
Deren Yang ◽  
...  

2009 ◽  
Vol 130 (20) ◽  
pp. 204110 ◽  
Author(s):  
A. Paarmann ◽  
T. Hayashi ◽  
S. Mukamel ◽  
R. J. D. Miller

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