TY - GEN
T1 - Yb:KLuW channel waveguide lasers passively Q-switched by evanescent-field interaction with carbon nanotubes
AU - Bae, Ji Eun
AU - Park, Tae Gwan
AU - Kifle, Esrom
AU - Mateos, Xavier
AU - Aguiló, Magdalena
AU - Díaz, Francesc
AU - Romero, Carolina
AU - Vázquez de Aldana, Javier Rodríguez
AU - Rotermund, Fabian
N1 - Publisher Copyright:
© 2019 IEEE
PY - 2019
Y1 - 2019
N2 - Highly efficient and compact pulsed laser sources have tremendous potential for integrated photonic devices in numerous applications including spectroscopy, metrology and microscopy. Yb3+-doped monoclinic doubletungstate crystals exhibit broad and large absorption and emission cross-sections and extremely low quantum defects. Channel waveguide structures have been actively studied for miniaturization of laser systems and efficient fundamental-mode laser operation with low lasing thresholds. One of the powerful methods to fabricate waveguide structures in a transparent material is the femtosecond direct laser writing (fs-DLW). Recently, pulsed waveguide lasers utilizing saturable absorbers (SAs) have been demonstrated with SESAM and low-dimensional carbon nanostructures. [1-3] Intrinsic characteristics such as ultrafast response, broadband nonlinear absorption and flexibility for integration make single-walled carbon nanotubes (SWCNTs) and graphene unique for various types of pulsed lasers. Placing a SA between the waveguide and the laser mirror results in additional intracavity losses and Q-switching instabilities due to thermal loads through direct-field interaction with the SA. Therefore, the damage-free coupling and the potential of a monolithic design including SAs in compact lasers are highly desired. Here we demonstrate the first Q-switched operation of the Yb-doped channel waveguides based on evanescent-field interaction with SWCNTs and compare with a direct-field interaction scheme. A surface circular cladding waveguide with a vertical width of 50 μm is inscribed in the 5 at.% Yb3+-doped KLu(WO4)2 crystal by fs-DLW (employing 120-fs / 65-nJ / 1-kHz pulses at a wavelength of 795 nm). Arc-discharged SWCNTs are spin-coated on top of the Yb:KLuW waveguide or on output couplers. A 982-nm tapered amplifier diode is used as the pump source. The polarization and power of the pump beam are controlled by a polarizer and two λ/2 wave plates. The 2.88-mm-long laser cavity consists of the Yb:KLuW channel waveguide and two mirrors directly attached to both end facets of the waveguide for two interaction schemes with SWCNTs, as shown in Fig. 1(a).
AB - Highly efficient and compact pulsed laser sources have tremendous potential for integrated photonic devices in numerous applications including spectroscopy, metrology and microscopy. Yb3+-doped monoclinic doubletungstate crystals exhibit broad and large absorption and emission cross-sections and extremely low quantum defects. Channel waveguide structures have been actively studied for miniaturization of laser systems and efficient fundamental-mode laser operation with low lasing thresholds. One of the powerful methods to fabricate waveguide structures in a transparent material is the femtosecond direct laser writing (fs-DLW). Recently, pulsed waveguide lasers utilizing saturable absorbers (SAs) have been demonstrated with SESAM and low-dimensional carbon nanostructures. [1-3] Intrinsic characteristics such as ultrafast response, broadband nonlinear absorption and flexibility for integration make single-walled carbon nanotubes (SWCNTs) and graphene unique for various types of pulsed lasers. Placing a SA between the waveguide and the laser mirror results in additional intracavity losses and Q-switching instabilities due to thermal loads through direct-field interaction with the SA. Therefore, the damage-free coupling and the potential of a monolithic design including SAs in compact lasers are highly desired. Here we demonstrate the first Q-switched operation of the Yb-doped channel waveguides based on evanescent-field interaction with SWCNTs and compare with a direct-field interaction scheme. A surface circular cladding waveguide with a vertical width of 50 μm is inscribed in the 5 at.% Yb3+-doped KLu(WO4)2 crystal by fs-DLW (employing 120-fs / 65-nJ / 1-kHz pulses at a wavelength of 795 nm). Arc-discharged SWCNTs are spin-coated on top of the Yb:KLuW waveguide or on output couplers. A 982-nm tapered amplifier diode is used as the pump source. The polarization and power of the pump beam are controlled by a polarizer and two λ/2 wave plates. The 2.88-mm-long laser cavity consists of the Yb:KLuW channel waveguide and two mirrors directly attached to both end facets of the waveguide for two interaction schemes with SWCNTs, as shown in Fig. 1(a).
UR - http://www.scopus.com/inward/record.url?scp=85084540980&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85084540980
SN - 9781728104690
T3 - Optics InfoBase Conference Papers
BT - The European Conference on Lasers and Electro-Optics, CLEO_Europe_2019
PB - Optica Publishing Group (formerly OSA)
T2 - The European Conference on Lasers and Electro-Optics, CLEO_Europe_2019
Y2 - 23 June 2019 through 27 June 2019
ER -