Compact, broadband, and efficient LP01 -LP11a mode converter based on cascaded asymmetric Y-junction

Abstract

In this paper, a compact and broadband mode converter, which can achieve efficient LP01-LP11a mode conversion, is demonstrated with cascaded asymmetric Y-junction in polymer waveguide. Our typical fabricated converter has a compact footprint of 1.5 mm × 14 µm and shows a mode conversion efficiency larger than ~ 98%, a crosstalk less than ~ −17.5 dB, and an insertion loss lower than ~ 5.8 dB for both x and y polarizations over the C + L band. Our proposed mode converter could find applications in broadband mode-division multiplexing transmission systems.

Johnson-noise-limited cancellation-free microwave impedance microscopy with monolithic silicon cantilever probes

“…Our approach significantly lowers the technical and economic barriers to high-performance MIM. Detailed designs and resources are available in Methods and our repository 43 , which we hope will facilitate a broad uptake of MIM in the condensed matter physics, microelectronics, and material sciences community. Moreover, since goldcoated silicon probes are widely used to study biological and chemical samples in complex environments 44 , our demonstration extends MIM's applicability to these domains, opening avenues for insights into a plethora of topics 22,45,46 .…”

“…The design and Gerber files of the impedance matching and mixer-INA PCB can be found in our repository 43 . We use a half-wave resonator made of a 100 mm-long RG-178 coax that gives rise to matched frequencies 1 GHz apart.…”

Aggregation of oligomeric Ir photosensitizers promotes efficient and long-lifetime photocatalytic hydrogen evolution

“…63,64 Inspired by the phenomenon of natural aggregation luminescence, 65 we previously synthesized oligomeric Ir photosensitizers via the copolymerization of [Ir(ppy) 2 (dabpy)](PF 6 ) with ODPA, which achieved a simultaneous increase in photocatalytic water splitting activity and stability due to the intramolecular interaction between adjacent [Ir(ppy) 2 (dabpy)](PF 6 ) molecules within the oligomer and the effect of large steric hindrance from the oligomer chains. 66 To further enhance the oligomeric structural effect on photocatalysis, herein, four kinds of oligomeric Ir photosensitizers were designed by tuning the structure of the anhydride linkers, namely (1,4,5,8-naphthalenetetracarboxylic dianhydride (NPTA), 3,3 0 ,4,4 0 -biphenyl tetracarboxylic dianhydride (BPDA), 4,4 0 -oxydiphthalic anhydride (ODPA), and hydroquinone diphthalic anhydride (HQDA)). The results show that in addition to the intramolecular interaction between adjacent [Ir(ppy) 2 (dabpy)](PF 6 ), oligomeric photosensitizers also aggregate with each other, which enables the coupling of neighboring oligomers through conformational adjustment.…”