Boosting the Non Linear Optical Response of Carbon Nanotube Saturable Absorbers for Broadband Mode‐Locking of Bulk Lasers

Abstract

Single‐walled carbon‐nanotube absorbers are experimentally demonstrated for laser mode‐locking. A saturable absorber device is used to mode‐lock three different bulk solid‐state lasers in a 500 nm‐wide wavelength interval. The devices exhibit a low saturation fluence of <10 µJ cm−2, low scattering losses, and an exceptionally rapid relaxation, with time constants reaching <100 fs. The latter two properties are explained by a decreased curling tendency and increased tube‐to‐tube interactions of the nanotubes, respectively. These properties are the result of an optimized manufacturing procedure in combination with the use of a starting material with a higher microscopic order. The decreased scattering enables universal use of these devices in bulk solid‐state lasers, which tend to be highly sensitive against non‐saturable device losses as caused by scattering. The favorable saturable absorption properties are experimentally verified by mode‐locking the three lasers, which all exhibit near transform‐limited performance with about 100 fs pulse duration. The complete and unconditional absence of Q‐switching side bands verifies the small saturation fluence of these devices.

Saturable Absorber Reflectors Based on Guided-mode Resonance in Slot Waveguides

“…반도체 기반의 포화 흡수체는 많은 연구의 대상이 되어왔으며 [3,4] , 최근에는 탄 소나노튜브(CNT) 박막을 포화흡수체로 사용하는 연구가 활 발히 이루어지고 있다 [5] . CNT …”

Fiber-based laser frequency combs

“…[22]. Since then, many various setups were presented, based on Erbium and Ytterbium-doped fibers, as well as bulk gain media [23][24][25].…”

High-power Ultrafast Solid-state Laser Using Graphene Based Saturable Absorber

“…molecular beam epitaxy) [2][3] and subsequent post-processing to reduce recovery time [2][3]. Single wall carbon nanotubes [4][5][6][7][8][9][10][11][12][13] and more recently, graphene [13][14][15][16][17][18][19] based saturable absorbers have attracted great attention for ultrafast pulse generation, due to their unique properties, such as sub-picosecond recovery time, broadband operation, low saturation intensity, easy fabrication and integration. In particular, graphene based saturable absorbers (GSA) are attractive SAs because they do not require bandgap engineering [13][14][15][16][17][18][19][20][21][22][23][24][25], due to the linear band dispersions [20].…”