53 research outputs found
Crystal structure of 3-{[4-(dimethylamino)phenyl]amino}-5-{[4-(dimethylamino)phenyl] aminothiocarbonyl}- 1,2-dithiol-1-ium-4-thiolate, C4S3SH(NHC6H4N(CH3)2)2.
Crystal structure of 4- methylthio-3-(phenylamino)-5- (phenylaminothiocarbonyl)-1,2-dithiol-1-ium trifluoromethanesulfonate, C4S3(NHC6H5)2(SCH3)(SO3CF3).
Crystal structure of 3H-4- (phenacylthio)-5-(phenylaminothiocarbonyl)- 3-(phenylimino)-1,2-dithiol, C4S3(NHC6H5)(NC6H5)(SCH2COC6H5).
Longitudinal data analysis of emotions of first-year students in an international degree programme
The following chapter investigate the assessment and development of students’ study paths and skills in a variety of disciplines. The final three chapters present research on student emotions and cultural perspectives, including mixed and multi-method empirical approaches. A key text for those keeping up with the current advances in the field
Universal dynamics and deterministic switching of dissipative Kerr solitons in optical microresonators
Temporal dissipative Kerr solitons in optical microresonators enable the generation of ultrashort pulses and low-noise frequency combs at microwave repetition rates. They have been demonstrated in a growing number of microresonator platforms, enabling chip-scale frequency combs, optical synthesis of low-noise microwaves and multichannel coherent communications. In all these applications, accessing and maintaining a single-soliton state is a key requirement one that remains an outstanding challenge. Here, we study the dynamics of multiple-soliton states and report the discovery of a simple mechanism that deterministically switches the soliton state by reducing the number of solitons one by one. We demonstrate this control in Si3N4 and MgF2 resonators and, moreover, we observe a secondary peak to emerge in the response of the system to a pump modulation, an effect uniquely associated with the soliton regime. Exploiting this feature, we map the multi-stability diagram of a microresonator experimentally. Our measurements show the physical mechanism of the soliton switching and provide insight into soliton dynamics in microresonators. The technique provides a method to sequentially reduce, monitor and stabilize an arbitrary state with solitons, in particular allowing for feedback stabilization of single-soliton states, which is necessary for practical applications
Scalable and Reconfigurable Optical Tap-Delay-Line for Multichannel Equalization and Correlation of 20-Gbaud QPSK signals Using Nonlinear Wave Mixing and a Microresonator Kerr Frequency Comb
We demonstrate a scalable and reconfigurable optical TDL for multichannel equalization and correlation of 20-Gbaud QPSK signals using nonlinear wave mixing and a Kerr frequency comb. The two/three-tap OTDL is demonstrated to simultaneously equalize a first signal and to search two/three-symbol patterns on another channel
Orthogonally polarized frequency comb generation from a Kerr comb via cross-phase modulation
We experimentally demonstrate that a single microresonator can emit two orthogonally polarized individually coherent combs: (i) a strong polarized soliton comb and (ii) an orthogonally polarized continuous wave seeded weaker comb, generated from the first one via cross-phase modulation, sharing the repetition rate of the soliton comb. Experimental results show that the power of the transverse electric-polarized seed can be well below the threshold of comb generation (e.g., 0.1 mW). In addition, simulations show that a dark pulse could be generated in the anomalous dispersion regime by a bright soliton when the two orthogonally polarized modes have the same group velocity in the microresonator. (C) 2019 Optical Society of Americ
Experimental demonstration of three-fold wavelength multicasting of a 64-QAM 120 Gbit/s data channel using a Kerr frequency comb and nonlinear wave mixing
We experimentally demonstrate three-fold wavelength multicasting of a 64-quadrature-amplitude-modulation (QAM), 120-Gbit/s data channel using a microresonator Kerr frequency comb and nonlinear wave mixing. The multicasting is achieved with a data signal and four comb lines serving as the pump lasers in a periodically poled lithium niobate (PPLN) waveguide. Minimal extra phase noise from the pumps is introduced into the multicast copies due to the mutual coherence between the Kerr comb lines. All three multicast copies achieve a bit-error rate (BER) <= 3.5E-3, which is below the forward-error-correction threshold. Both the error vector magnitude (EVM) and BER performances show <0.5-dB optical signal-to-noise ratio (OSNR) penalty for the multicast copies compared to the original data signal
- …