OSA (FiO/LS) 2016 Shun Fujii

[FTh5G.3] "Silica-Chip-Based Continuum Generation for Frequency Comb Self-Referencing" (NIST)
This is a continuation of the research presented at this year's CLEO on using dispersive waves in silica waveguides to extend the bandwidth of supercontinuum light. The waveguide was fabricated by Vahala's group, and the position of the dispersive wave can be controlled at the lithography stage. This time, for the purpose of f-2f self-referencing, they even measured the carrier offset frequency using the dispersive wave to spread the continuum over more than one octave.

[FTh5G.2] "Experimental Demonstration of Inserting Phase-Locked Lines into Kerr Combs using Electro-Optical Modulation" (A. Wilner )
By applying EO modulation to the car comb generated by the SiN ring resonator, a new frequency can be generated that fills the space between the car combs. The major advantage of this is that the FSR spacing, which is uniquely determined by the resonator length, can be adjusted and lower noise can be achieved. Furthermore, the difference in frequency between the two combs generated by EO modulation was measured, and the error signal of the signal was measured for communication applications. The idea of controlling the number of combs by modulating optical car combs with RF signals is very interesting. In particular, the fact that the phase noise is not degraded before and after modulation is also an advantage.

[FTh5G.6] "Ultraviolet Second Harmonic Generation in Aluminum Nitride Microring Resonators" (Air Force Research Laboratory Laboratory)
UV generation by the second harmonic was confirmed using an aluminum nitride resonator with a Q-value of about 9*103 in the 780 nm band and a Ti:Sapphire femtosecond laser pulse. However, this was not the case with the AlN waveguide. However, this was due to the AlN waveguide and not to the resonator. Harmonic generation in the resonator may be possible if the Q-value at short wavelengths is improved and a high-power CW laser is used, but it does not appear to be possible at present.

[FTu5D.2] "Mid-Infrared Dual-Comb Source Using a Silicon Microresonator" (Columbia Univ.)
A report on dual comb spectroscopy in the mid-infrared band, which was presented at the post-deadline of this year's CLEO. Although the contents were almost the same, microcomb spectroscopy in the mid-infrared band is a field that is attracting a lot of attention, and there were many people in the audience. In the same session, there was also a presentation of a study (FTu5D.3) on the use of SiN waveguides to extend the supercontinuum of 1.5-μm pumps to the mid-infrared band.

[FTu5D.5] "Mid-infrared ultra high Q factors in fluoride crystalline microresonators" (EPFL)
A report on the achievement of high Q-values exceeding 108 in the mid-infrared band in crystal resonators using fluoride materials (Ca/Mg/Ba/SrF2). Using chalcogenite (As2S3) tapered fiber, 108 was measured in the above resonators except for MgF2, which was limited to 107 due to multiphoton absorption. This result shows the possibility of using fluoride WGM resonators as well as ring resonators such as silicon and silicon nitride in future research targeting the mid-infrared band.