使用多壁碳纳米管被动调Q S波段铥氟光纤激光器

197 浏览量更新于2024-08-30 收藏 513KB PDF 举报

"这篇论文提出并演示了一种稳定被动Q开关S波段铥氟光纤激光器(TFFL)，采用多壁碳纳米管(MWCNT)基饱和吸收器(SA)。该激光器的中心发射波长为1486.4纳米，输入功率范围在87.1至126.6毫瓦之间。输出脉冲的重复频率和脉宽范围分别为30.1至40.0千赫兹和9.0至3.2微秒，最大脉冲能量达到28.9纳焦。据作者所知，这是首次成功地使用MWCNT基SA实现被动Q开关S波段TFFL的展示。" 文章涉及的关键知识点包括： 1. **被动Q开关技术**：Q开关是一种用于控制激光器脉冲产生的技术，通过改变激光谐振腔内的损耗来控制增益介质的量子效率。被动Q开关是其中一种，它利用非线性吸收材料（如本文中的MWCNT）自然地增加腔内损耗，产生短而强烈的脉冲。 2. **铥氟光纤激光器(TFFL)**：铥氟光纤激光器是一种使用铥离子作为激活剂的光纤激光器，工作在近红外区域，通常在1.9到2.1微米之间。铥氟光纤激光器因其高功率、窄线宽和良好的热管理特性而在各种应用中受到关注。 3. **S波段激光**：S波段是指在通信和光谱学中使用的特定电磁波谱的一部分，大约在3000到30000GHz（或1到10微米）之间。在这个波段工作的激光器可以应用于远程感测、医学成像和高速通信等领域。 4. **多壁碳纳米管(MWCNT)**：MWCNT是一种由多个同心碳纳米管层组成的结构，具有独特的电学和光学性质，使其成为制造高效饱和吸收器的理想材料。在本文中，MWCNT用作Q开关，因为它能有效地吸收激光能量并快速恢复，从而产生短脉冲。 5. **饱和吸收器(SA)**：饱和吸收器是Q开关的核心组件，当激光功率达到一定阈值时，其吸收特性会饱和，允许激光脉冲通过。MWCNT的这种特性使得激光器能够在保持稳定的同时产生脉冲。 6. **激光性能参数**：论文中提到的激光器输出脉冲的重复频率和脉宽范围以及最大脉冲能量，这些都是衡量激光器性能的重要指标。较高的重复频率意味着每秒发射的脉冲数量更多，而较窄的脉宽表示每个脉冲的能量更集中，最大脉冲能量则反映了激光器的峰值功率。 7. **应用前景**：随着对信息容量和带宽需求的增长，现有的通信系统面临限制。被动Q开关S波段铥氟光纤激光器因其独特的优势，可能在光纤通信、遥感、医疗和工业加工等领域的未来发展中起到重要作用。这项研究展示了MWCNT基饱和吸收器在被动Q开关铥氟光纤激光器中的应用潜力，这为S波段激光技术的发展提供了新的思路和可能的解决方案。

Passively Q-switched S-band thulium fluoride fiberlaser

with multi-walled carbon nanotube

H. Ahmad* and S. A. Reduan

Photonics Research Centre, University of Malaya, Kuala Lumpur 50603, Malaysia

*Corresponding author: harith@um.edu.my

Received October 7, 2017; accepted December 1, 2017; posted online January 2, 2018

A stable, passively Q-switched thulium fluoride fiber laser (TFFL) using a multi-walled carbon nanotube

(MWCNT)-based saturable absorber (SA) for operation in the S-band region is proposed and demonstrated.

The proposed TFFL has a central lasing wavelength of 1486.4 nm and an input power range of 87.1–126.6 mW.

The output pulses have a repetition rate and pulse width range of 30.1–40.0 kHz and 9.0–3.2 μs, respectively,

with a maximum pulse energy of 28.9 nJ. This is the first time, to the author’s knowledge, of the successful

demonstration of a passively Q-switched S-band TFFL using an MWCNT-based SA.

OCIS codes: 060.0060, 060.2430, 060.4370, 140.3510, 140.3540.

doi: 10.3788/COL201816.010609.

Recently, increased demands for information capacity

and bandwidth have incurred significant limitations on

existing communications infrastru cture. Among the key

reasons for this is the over-dependence on the C-band

of optical fiber systems

[1]

. As such, substantial research

efforts are now focused toward exploiting the L-band

[2,3]

1.0 μm

[4,5]

, and 2.0 μm

[6,7]

regions to increase bandwidth

availability. Furthermore, recent developments have also

seen the exploration of the S-band as a viable region for

expanding the current communications bandwidth to

cater to this increasing demand

[1]

In communication systems particularly, pulsed sources

operating at different bandwidths are crucial for the trans-

mission of data. In this regard, Q-switched fiber lasers are

highly desired for use in fiber laser systems due to their

compact size, low fabrication, and operating cost as well

as high flexibility

[8,9]

. Additionally, the output generated

by these lasers have longer pulse widths and higher pulse

energies, both of which are desired for communications ap-

plications

[10]

, and finds significant applications in optical

imaging, material processing, medicine, and environmen-

tal sensing

[11–13]

Q-switching in fiber lasers can be realized through either

active or passive means. Active Q-switching is achieved by

modulating the output of the laser cavity using an exter-

nal device, giving a high degree of control over various out-

put parameters such the repetition rate and pulse width

[14]

However, this technique requires complex electronics,

significantly increasing the size and cost of the laser

[15]

Passive Q-switching on the other hand offers less control

over the outp ut parameters, but is advantageous in terms

of its compact form factor, low-cost, and flexibility of

operation, thereby making them a preferred solution for

many real-world operations

[16]

One of the earliest means of generating passively

Q-switched pulses was the use of semicon ductor saturable

absorber mirrors (SESAMs)

[17,18]

. While initially suitable

for obtaining the desired output, its difficult integration

into most fiber cavity designs, as well as limited band-

width and high fabrication cost

[19,20]

, spurred researchers

to explore new means to generate passively Q-switched

pulses. Research efforts thus begin to focus on saturable

absorbers (SAs) and the discovery of 2D materials such

as single-walled carbon nanotubes (SWCNTs) provided

a significant breakthrough in the search for new SA ma-

terials

[21,22]

. This encouraged researchers to search for new

SA-capable materials, including graphene

[13,23]

and more

recently transition metal dichalcogenides (TMDs)

[15]

topological insulators (TIs)

[24–26]

, and even exotic materials

such as black phosphorus

[27]

. Recent advances have also

seen the development of multi-walled carbon nanotubes

(MWCNTs)

[28]

as SA materials, owing to their good ther-

mal characteristics and higher mechanical strength as well

as a better thermal stability and high photon absorption

per nanotube efficiency due to the high multi-walls mass

density

[29]

. This high density also affords MWCNTs a

higher thermal damage threshold as the outer walls can

protect the inner walls from damage or oxidation

[29]

In this work, a passively Q-switched thulium-fluoride

fiber laser (TFFL) operating in the S-band region and

incorporating an MWCNT-based SA is proposed and

demonstrated. To date, there have been only a few pas-

sively Q-switched fiber lasers in the S-band region re-

ported, and even fewer that operate at the shorter

wavelength range of the S-band region. It must be noted

that while there have been previou s works using erbium-

doped fibers (EDFs)

[2,24]

and depressed-cladding EDFs

(DC-EDFs)

[30,31]

as gain media in generating S-band pulsed

laser outputs with the assistance of SAs, most of these la-

sers are only capable of partial S-band operation, and re-

quire the aid of tunable bandpass filters (TBPFs). In this

work however, the combination of the thulium-fluoride

fiber (TFF) as a gain medium and MWCNT-based SA

has significant potential to generate passively Q-switched

pulses in the S-band region, with the use of the TFF giving

a large operational bandwidth from 1440 to 1500 nm.

COL 16(1), 010609(2018) CHINESE OPTICS LETTERS January 10, 2018

下载后可阅读完整内容，剩余4页未读，立即下载

weixin_38600253

粉丝: 6
资源: 904

使用多壁碳纳米管被动调Q S波段铥氟光纤激光器

高效3.2ns YAG/Nd∶YAG/Cr4+∶YAG键合晶体被动调Q径向激光器研究

四束输出被动Q开关Nd:YAG/Cr4+:YAG复合激光器

扩散焊接单晶Nd:YAG非平面环振荡器的被动调Q单频输出

Dual-loss-modulated passively Q-switched Tm:LuAG laser with multi-walled carbon nanotube and monolayer graphene

A diode-pumped passively Q-switched Tm,Ho:YAP laser with a single-walled carbon nanotube

A passively Q-switched Yb:YAG laser with a single-walled carbon nanotube saturable absorber

Passively Q-switched femtosecond-laser-written thulium waveguide laser based on evanescent field interaction with carbon nanotubes

Passively Q-switched Tm-doped f iber lasers with carbon nanotubes

Self-Q-switched and wavelength-tunable tungsten disulfide-based passively Q-switched Er:Y2O3 ceramic lasers

Wideband tunable passively Q-switched fiber laser at 2.8 μm using a broadband carbon nanotube saturable absorber

最新资源