We demonstrate robust soliton crystals generation with a fixed frequency pump laser through a thermoelectric-cooler-based thermal-tuning approach in a butterfly-packaged complementary-metal-oxide-semiconductor-compatible microresonator. Varieties of soliton crystal states, exhibiting "palm-like" optical spectra that result from the strong interactions between the dense soliton ensembles and reflect their temporal distribution directly, are experimentally observed by sweeping one cavity resonance across the pump frequency from the blue-detuned side by reducing the operating temperature of the resonator. Benefitting from the tiny intra-cavity energy change, repeatable interconversion between the chaotic modulation instability and stable soliton crystal states can be successfully achieved via simple tuning of the temperature or pump power, showing the easy accessibility and excellent stability of such soliton crystals. This work could facilitate microresonator-based optical frequency combs towards a portable, adjustable, and low-cost system while avoiding the requirements of delicate frequency-sweeping pump techniques.

We propose a new strip/slot hybrid waveguide with double slots, which exhibits a flat and low dispersion over a 1098-nm bandwidth with four zero-dispersion wavelengths. Dispersion of dual-slot silicon waveguide is mainly determined by mode transition from a strip mode to a slot mode rather than by material dispersion. Dispersion tailoring is investigated by tuning different structural parameters of waveguides. Moreover, nonlinear coefficient of dual-slot silicon waveguide and phase-matching condition in FWM are both explored in detail. The dual-slot waveguide can be used to generate supercontinuum with bandwidth extending up to 1630 nm pumped by femtosecond pulses. This waveguide will have a great potential for ultrabroadband signal processing applications from near-infrared region to mid-infrared region.

RVB) phase and the Pancharatnam-Berry (PB) phase. [11][12][13][14][15][16] The former phase is associated with the evolution of the propagation direction of light, and the latter is associated with the manipulation of the polarization state of light. In the past few years, photonic SHE has attracted considerable attention, and many important progresses have been reported. [17][18][19] A modified geometrical optics theory considering Berry phase and optical Magnus effect was constructed by K. Y. Bliokh and Y. P. Bliokh, which well described the spindependent splitting phenomenon. [20] Especially, the scheme of the corresponding experiment has also been suggested. Besides, the research on quantum spin Hall effect of light are also reported. [21] The intrinsic quantum spin Hall effect of pure free-space light is revealed, and unusual transverse spin in evanescent waves are illuminated. However, measurements of the photonic SHE in approaches based on the RVB phase are difficult due to the extremely tiny spin-orbit interactions involving photons and matter. [2,[22][23][24] This limitation has seriously hindered the development of optical spin-dependent devices.Metasurfaces consist of subwavelength units with electromagnetic responses that mainly stem from the designed structures rather than the constituent materials, leading to many extraordinary properties. Thus, metasurfaces provide an effective approach to accurately manipulate the electromagnetic wave at the subwavelength scale. [25][26][27][28][29] Moreover, utilizing the nanoatennas to obtain the PB phase, the metasurface is able to dramatically enhance the spin-orbital interactions compared with traditional approaches based on the RVB phase. [13,[30][31][32] This unique property makes the observation and measurement of the photonic SHE much easier, and many experiments and studies of the photonic SHE have been carried out. [33][34][35][36][37] Li et al. observed an obvious transverse spin-dependent splitting in a gold nanorod-based metasurface. [32] Ke et al. proposed a composite metasurface to produce longitudinal spin-dependent splitting. [37] However, the above investigations mainly focused on only 1D modulation (transverse or longitudinal), which have limitations on multidimensional manipulation of spin photons. Recently, a method of multidimensional spin-dependent splitting was proposed with a meta-lens. [38] In this method, an extra The photonic spin Hall effect, originating from photonic spin-orbit interactions, has attracted considerable research interest due to its potential for applications in spin-controlled nanophotonics. However, most research efforts have focused only on 1D modulation, including transverse or longitudinal spin-dependent splitting. Here, a novel method is proposed for multidimensional spin-dependent splitting on a single-layer dielectric metasurface. Due to the interplay of the Pancharatnam-Berry phase and dynamic phase, the longitudinal focusing and transverse shifting of the different spin state photons can be simultaneously achi...

Ship measurements made 2 days after the passage of a tropical depression (TD) in the South China Sea (SCS, April 2011) showed two contrasted responses of the partial pressure of CO 2 at sea surface (pCO 2,sw ). In low sea-surface salinity (SSS) water, pCO 2,sw was low (349 6 7 latm), and the area was a carbon sink (24.7 6 1.8 mmol CO 2 m 22 d 21 ), whereas in water with high SSS and chlorophyll a and low dissolved oxygen and sea surface temperature, pCO 2,sw was higher than for normal SCS water (376 6 8 versus 362 6 4 latm) and the area was a carbon source (1.2 6 3.1 mmol CO 2 m 22 d 21 ). Satellite data showed two large areas of low SSS before the TD, which were likely influenced by rainfall, and these areas were considered to have low pCO 2,sw because of their low SSS. The high pCO 2,sw after the TD is explained by the uplifting to the surface of deeper and CO 2 -rich water, due to winds accompanied by the TD. The difference in sea-air CO 2 flux between the TD-affected area and the lower-SSS water was 1.99 1 4.70 5 6.7 mmol CO 2 m 22 d 21 , indicating a 100% change caused by the TD compared to the average seasonal value in spring in southern SCS (3.3 6 0.3 mmol CO 2 m 22 d 21 ). Undersaturation of CO 2 prior to the TD due to dilution by freshwater and the preexisting cold eddy, and slow translation speed of the TD, are considered to account for the CO 2 flux change.