Session Index

Quantum Electronics and Laser Technology

Lase Science and Technology
Friday, Dec. 8, 2017  08:30-10:15
Presider: Ming-Dar Wei;Te-Yuan Chung
Room: International Research Building IR3003(3F)
08:30 - 09:00 Paper No.  2017-FRI-S0303-I001
Invited Speaker:
Ju Han Lee
Topological Insulators for 2-μm Pulsed Fiber Lasers
Ju Han Lee

I review our group’s recent investigation results on the use of saturable absorbers based on bulk-structured topological insulators for the implementation of pulsed fiber lasers in the 2 μm spectral region. Our research focus was given to Bi2Te3 and filled skutterudite of In0.25Co4Sb12.

09:00 - 09:30 Paper No.  2017-FRI-S0303-I002
Invited Speaker:
Yung Fu Chen
Broad expansion of optical frequency combs by self-Raman scattering in coupled-cavity self-mode-locked monolithic lasers
Yung Fu Chen

In this work we numerically analyze and experimentally accomplish the broad expansion the optical frequency comb (OFC) by the self-Raman scattering in a coupled-cavity self-mode-locked (SML) monolithic Yb:KGW laser [1,2]. We firstly design a coated Yb:KGW crystal to generate the OFC in the SML operation. The crystal length shorter than 3.00 mm is used to avoid significant re-absorption losses. With a crystal length of 2.93 mm, the SML repetition rate of 25.78 GHz is obtained. We then employ a partially reflective mirror to form a coupled cavity that was set to multiply the repetition rate to reach 128.9 GHz. Furthermore, the critical value of the coupled reflectivity for the generation of self-Raman scattering is systematically explored and found to be approximately 90%. Experimental results reveal that a coupled reflectivity of 95% can lead to the generation of the first- and second-order SRS in the gain medium at the lowest frequency mode. As a result, the OFC can be expanded up to 8.4 THz with the pulse width down to 53 fs, as shown in Fig. 1. The total output power for the fundamental and the Stokes waves can achieve 1.6 W at a pump power of 8.7 W. Previously, several groups demonstrated sub-100 fs Yb:KGW mode-locked lasers with the action of a semiconductor saturable absorber mirror (SESAM) or Kerr-lens. The repetition rates in these earlier works were in the range of 30-80 MHz, whereas the present method can generate the repetition rate greater than 100 GHz. Our exploration confirms that the optical spectra generated by the SML and SRS process can be linked together to obtain an ultrahigh-repetition-rate broadband OFC.  

09:30 - 09:45 Paper No.  2017-FRI-S0303-O001
Yuan-Yao Lin Generation of optical vortices in a degenerate optical resonator with an intra-cavity spiral phase plate
Chia-Chi Yeh;Hsien-Che Lee;Yuan-Yao Lin

Generating optical vortices using a degenerate optical resonator with an intra-cavity spiral phase plate (SPP) was proposed and realize on diode-pumped solid state laser system. The rays retracing skewed V-shaped paths in the resonator are phase-locked to form vortex laser with wavefront dislocation mirroring the topological charge of the SPP.

09:45 - 10:00 Paper No.  2017-FRI-S0303-O002
Hsing-Chih Liang Exploring antiphase dynamics in a dual-polarization passively Q-switched Nd:YLF laser
Hsing-Chih Liang

The stable condition for π-polarization emission in an a-cut Nd:YLF laser is numerical analyzed to find the critical pump power for generating the orthogonally polarized emission. With the numerical analysis, an orthogonally polarized dual-wavelength PQS laser has been originally designed and an interesting phenomena of antiphase dynamics have been observed.

10:00 - 10:15 Paper No.  2017-FRI-S0303-O003
Tzu-Ying Tai Collective lasing behavior in monolithic GaN-InGaN core-shell nanorod lattice
Tzu-Ying Tai;Hao-Chung Kuo

We realized a room temperature laser by monolithic GaN-InGaN core-shell nanorod lattice with its threshold pumping density being 140 kW/cm2. The narrow mode spacing between lasing peaks suggested a strong coupling between adjacent whisper gallery modes. Mode switching was observed under different excitation area photoluminescence measurement.