scholarly journals Highly Damage-Resistant Thin Film Saturable Absorber Based on Mechanically Functionalized SWCNTs

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Daewon Kang ◽  
Sourav Sarkar ◽  
Kyung-Soo Kim ◽  
Soohyun Kim
Keyword(s):  
Thin Film ◽  
Raman Spectroscopy ◽  
Fiber Laser ◽  
Thermal Damage ◽  
Structural Integrity ◽  
Modulation Depth ◽  
Stable Operation ◽  
Laser Operation ◽  
Free Standing ◽  
Film Type

AbstractThin-film saturable absorbers (SAs) are extensively used in mode-locked fiber laser due to the robust and simple application methods that arise because SAs are alignment-free and self-standing. Single-walled carbon nanotubes (SWCNTs) are the most suitable low dimensional material uesd for SAs because of their high nonlinearity and the wavelength control of absorption based on tube diameters. The most challenging problem with the use of CNT-based thin film SAs is thermal damage caused during high power laser operation, which mainly occurs due to aggregation of CNTs. We have demonstrated improved thermal damage resistance and enhanced durability of a film-type SA based on functionalization of SWCNTs, which were subjected to a mechanical functionalization procedure to induce covalent structural modifications on the SWCNT surface. Increased intertube distance was shown by X-ray diffraction, and partial functionalization was shown by Raman spectroscopy. This physical change had a profound effect on integration with the host polymer and resolved aggregation problems. A free-standing SA was fabricated by the drop casting method, and improved uniformity was shown by scanning electron microscopy. The SA was analyzed using various structural and thermal evaluation techniques (Raman spectroscopy, thermogravimetric analysis, etc.). Damage tests at different optical powers were also performed. To the best of our knowledge, a comprehensive analysis of a film-type SA is reported here for the first time. The partially functionalized SWCNT (fSWCNT) SA shows significant structural integrity after intense damage tests and a modulation depth of 25.3%. In passively mode-locked laser operation, a pulse width of 152 fs is obtained with a repetition rate of 77.8 MHz and a signal-to-noise ratio of  75 dB. Stable operation of the femtosecond fiber laser over 200 h verifies the enhanced durability of the fSWCNT SA.

scholarly journals Highly efficient mode-locked and Q-switched Er3+-doped fiber lasers using a gold nanorod saturable absorber

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yin-Wen Lee ◽  
Chien-Ming Chen ◽  
Wei-Hsiang Chuang ◽  
Ching-Yi Cho ◽  
Cheng-Hsien Yu ◽  
...  
Keyword(s):  
Thin Film ◽  
Fiber Laser ◽  
Saturable Absorber ◽  
Fiber Lasers ◽  
Modulation Depth ◽  
Maximum Energy ◽  
Gold Nanorod ◽  
Dual Function ◽  
Saturation Intensity ◽  
Pulsed Fiber Laser

AbstractMode-locked and Q-switched pulsed fiber laser sources with wavelengths of 1.55 μm are widely used in various fields. Gold nanorods (GNRs) have been applied in biomedicine and optics owing to their biocompatibility, easy fabrication, and unique optical properties. This paper presents the analysis of a saturable absorber based on a colloidal gold nanorod (GNR) thin film for dual-function passively mode-locked and Q-switched 1.55-μm fiber lasers. The colloidal GNR thin film possesses superior properties such as a wide operating wavelength range, large nonlinear absorption coefficient, and a picosecond-order recovery time. Its modulation depth and saturation intensity at 1.55 μm are 7.8% and 6.55 MW/cm2, respectively. Passive mode-locked or Q-switched laser operation is achieved by changing the number of GNR thin-film layers. The advantages of these high-quality GNRs in mode-locked and Q-switched fiber lasers with record-high slope efficiency are verified by conducting comprehensive material and laser dynamic analyses. The self-starting mode-locked fiber laser with an efficiency as high as 24.91% and passively Q-switched fiber laser with the maximum energy of 0.403 μJ are successfully demonstrated. This paper presents the novel demonstration of reconfigurable mode-locked and Q-switched all-fiber lasers by incorporating colloidal GNR thin films.

scholarly journals A Simple and Efficient Method to Fabricate Graphene 2D Nanomaterial into a thin Film to Serve as a Saturable a bsorber for Fiber Laser Application

2018 ◽  
Vol 7 (4.15) ◽  
pp. 298
Author(s):  
Yousif I. Hammadi ◽  
Tahreer S. Mansour
Keyword(s):  
Thin Film ◽  
Fiber Laser ◽  
Saturable Absorber ◽  
Modulation Depth ◽  
Laser Cavity ◽  
Pulse Generation ◽  
Saturable Absorbers ◽  
Polarization Insensitive ◽  
Graphene Saturable Absorber ◽  
Pulsed Fiber Laser

A passively pulsed fiber laser using saturable absorbers such as graphene has been increased dramatically in recent years. Up to now, researchers have been proposed many methods to fabricate graphene saturable absorber such as (evanescent coupling structure, electrochemical exfoliation, and mechanical exfoliation) for light pulse generation in a fiber laser. However, each of these methods has got some limitations which reduce the saturable absorber performance and restrict its range of applications. In this paper, we propose a simple but very efficient fabrication way of graphene saturable absorber by converting graphene Nano powder into a thin film using polyvinyl alcohol (PVA) as a host material. The fabricated film can then be easily sandwiched between two fiber pigtails and inserted inside the laser cavity to form the saturable absorber. when compared with other methods, this method is much preferable because it provides saturable absorber with combat structure, maximum interaction area, reasonable insertion loss, polarization insensitive, controllable concentration, and safe to handle. The fabricated graphene saturable absorber in this paper was characterized and found to have a uniform distribution of the graphene nanomaterial in the PVA and have a modulation depth of 6.1% which make it a very promising saturable absorber for ultra-fast fiber laser demonstration.  

L-band femtosecond fiber laser with Cu2Te-PVA thin film

2021 ◽  
Vol 19 (1) ◽  
pp. 015101
Author(s):  
H Ahmad ◽  
N H Abdul Kahar ◽  
N F Norisham ◽  
S A Reduan ◽  
L Bayang
Keyword(s):  
Thin Film ◽  
Pump Power ◽  
Fiber Laser ◽  
Modulation Depth ◽  
Signal To Noise Ratio ◽  
Optical Absorption Measurement ◽  
Saturation Intensity ◽  
Nonlinear Optical Absorption ◽  
L Band ◽  
The Stability

Abstract For the first time, this research proposed a copper telluride (Cu2Te)-polyvinyl alcohol thin film as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) operating in the long-wavelength band (L-band). The nonlinear optical absorption measurement of Cu2Te thin film revealed a saturation intensity of 3.26 kW cm−2 and a modulation depth of 2.7%. Furthermore, the mode-locked pulse was successfully generated by integrating a Cu2Te thin film into the L-band cavity at a threshold pump power of 135.61 mW with a center wavelength and pulse duration of 1565.48 nm and 770 fs, respectively. When observing the output mode-locked pulse, the pump power for the EDFL ranged from 135.61 mW to 201.28 mW, with the fundamental mode having a repetition rate 10.28 MHz. Furthermore, the magnitude of the signal-to-noise ratio was approximately 61.3 dB, indicating that the laser was stable with no significant fluctuations during the stability test. Overall, the findings showed that Cu2Te thin film has an excellent output and a promising candidate for an SA, implying that it could have a lot of potentials in pulsed laser application.

scholarly journals Highly Stable Passively Q-Switched Erbium-Doped All-Fiber Laser Based on Niobium Diselenide Saturable Absorber

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4303
Author(s):  
Ping Hu ◽  
Jiajia Mao ◽  
Hongkun Nie ◽  
Ruihua Wang ◽  
Baitao Zhang ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Saturable Absorber ◽  
Pulse Width ◽  
Nonlinear Optical ◽  
Modulation Depth ◽  
Transition Metal Dichalcogenide ◽  
Center Wavelength ◽  
Niobium Diselenide ◽  
Erbium Doped ◽  
Layered Transition Metal

A saturable absorber (SA) based on niobium diselenide (NbSe2), which is a layered transition metal dichalcogenide (TMD) in the VB group, is fabricated by the optically driven deposition method, and the related nonlinear optical properties are characterized. The modulation depth, saturable intensity, and nonsaturable loss of the as-prepared NbSe2 nanosheet-based SA are measured to be 16.2%, 0.76 MW/cm2, and 14%, respectively. By using the as-fabricated NbSe2 SA, a highly stable, passively Q-switched, erbium-doped, all-fiber laser is realized. The obtained shortest pulse width is 1.49 μs, with a pulse energy of 48.33 nJ at a center wavelength of 1560.38 nm. As far as we know, this is the shortest pulse duration ever obtained by an NbSe2 SA in a Q-switched fiber laser.

A Self‐Limited Free‐Standing Sulfide Electrolyte Thin Film for All‐Solid‐State Lithium Metal Batteries

2021 ◽  
pp. 2101985
Author(s):  
Gao‐Long Zhu ◽  
Chen‐Zi Zhao ◽  
Hong‐Jie Peng ◽  
Hong Yuan ◽  
Jiang‐Kui Hu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Lithium Metal ◽  
Free Standing ◽  
Lithium Metal Batteries

The Elastic Moduli of Silver Thin Films Measured with a New Microtensile Tester

1991 ◽  
Vol 239 ◽  
Author(s):  
J. Ruud ◽  
D. Josell ◽  
A. L. Greer ◽  
F. Spaepen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Diffraction Grating ◽  
Strain Measurement ◽  
Elastic Moduli ◽  
Two Dimensional ◽  
Bulk Crystals ◽  
Free Standing ◽  
Tensile Direction ◽  
Silver Thin Films

ABSTRACTA new design for a thin film microtensile tester is presented. The strain is measured directly on the free-standing thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography. The diffraction grating is two-dimensional, allowing strain measurement both along and transverse to the tensile direction. In principle, both Young's modulus and Poisson's ratio of a thin film can be determined. Ag thin films with strong <111> texture were tested. The measured Young moduli agreed with those measured on bulk crystals, but the measured Poisson ratios were low, most likely due to slight transverse folding of the film that developed during the test.

Combinatorial (Ba,Sr)TiO3 thin film growth: X-ray diffraction and Raman spectroscopy

2009 ◽  
Vol 106 (3) ◽  
pp. 034108 ◽  
Author(s):  
H. Bouyanfif ◽  
J. Wolfman ◽  
M. El Marssi ◽  
Y. Yuzyuk ◽  
R. Bodeux ◽  
...  
Keyword(s):  
Thin Film ◽  
Raman Spectroscopy ◽  
Film Growth ◽  
Thin Film Growth ◽  
Tio3 Thin Film ◽  
X Ray Diffraction ◽  
X Ray
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