1,449 research outputs found
Transient light waveguides deep into scattering media by transversal ultrasound
We present the concept of ultrasound-induced light waveguides based on transient ultrasound waves to partially offset strong light scattering. The extent and configuration of such waveguides is fundamentally limited only by ultrasound propagation losses
Femtosecond RMS timing jitter from 1 GHz InP on-chip mode-locked laser at 1550 nm
In this work, we analyze the timing stability of a 1 GHz InP on-chip monolithic mode-locked laser at 1550 nm. 504 fs RMS timing jitter is achieved by a hybrid mode-locking operation
Amplitude noise and RF response analysis of 1 GHz mode-locked pulses from an InP-based laser chip at 1550 nm
In this work, we investigate a 1 GHz InP-based hybrid mode-locked laser chip and find an amplitude noise of 0.036 percent. An RF response simulation of its custom-designed mounting PCB is performed providing power transmission between 86 and 92 percent
RF Analysis of a Sub-GHz InP-Based 1550 nm Monolithic Mode-Locked Laser Chip
We report a monolithic sub-GHz repetition rate
mode-locked laser with record low pulse-to-pulse RMS timing
jitter of 3.65 ps in the passive mode locking regime. We analyse
the optical pulse generation in passive and hybrid mode-locking
operating regimes, finding narrower RF tone linewidth in the
passive regime, attributed to the improved contact structure of
the gain sections. The noise performance is also characterized
in passive and hybrid regimes, showing RMS integrated timing
jitter of approximately 600 fs. For hybrid modelocking, the
repetition rate can be varied over a large range from 880 to 990
MHz. We observe broad pulse widths of few hundred
picoseconds attributed to the (long folded) waveguide
architecture and on-chip multimode interference mirrors. This
device subjects a stand-alone, ultra-compact, mode-locking
based clock source to realize frequency synthesizers operating
over a frequency range from sub-GHz up to approximately 15
GHz
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Encapsulation of graphene transistors and vertical device integration by interface engineering with atomic layer deposited oxide
We demonstrate a simple, scalable approach to achieve encapsulated graphene transistors with negligible gate hysteresis, low doping levels and enhanced mobility compared to as-fabricated devices. We engineer the interface between graphene and atomic layer deposited (ALD) AlO by tailoring the growth parameters to achieve effective device encapsulation whilst enabling the passivation of charge traps in the underlying gate dielectric. We relate the passivation of charge trap states in the vicinity of the graphene to conformal growth of ALD oxide governed by gaseous HO pretreatments. We demonstrate the long term stability of such encapsulation techniques and the resulting insensitivity towards additional lithography steps to enable vertical device integration of graphene for multi-stacked electronics fabrication.This work was supported by the EPSRC (Grant Nos. EP/K016636/1, GRAPHTED and EP/L020963/1) and the ERC (Grant No. 279342, InsituNANO). JAA-W acknowledges a Research Fellowship from Churchill College, Cambridge. JS acknowledges support from NUDT. ZAVV acknowledges funding from ESPRC grant EP/L016087/1. ACV acknowledges the Conacyt Cambridge Scholarship and the Roberto Rocca Fellowship. RW acknowledges EPSRC Doctoral Training Award (EP/M506485/1)
Prostate Cancer Foundation Hormone-Sensitive Prostate Cancer Biomarker Working Group Meeting Summary.
Androgen deprivation therapy remains the backbone therapy for the treatment of metastatic hormone-sensitive prostate cancer (mHSPC). In recent years, several treatments, including docetaxel, abiraterone + prednisone, enzalutamide, and apalutamide, have each been shown to demonstrate survival benefit when used upfront along with androgen deprivation therapy. However, treatment selection for an individual patient remains a challenge. There is no high level clinical evidence for treatment selection among these choices based on biological drivers of clinical disease. In August 2020, the Prostate Cancer Foundation convened a working group to meet and discuss biomarkers for hormone-sensitive prostate cancer, the proceedings of which are summarized here. This meeting covered the state of clinical and biological evidence for systemic therapies in the mHSPC space, with emphasis on charting a course for the generation, interrogation, and clinical implementation of biomarkers for treatment selection
Advantages of doubly polished thin sections for the study of microfossils in volcanic rock
Doubly polished thin sections, originally prepared for fluid inclusion studies, present great advantages in the study of microfossils in volcanic rocks. Better visibility and light conditions, variation in thickness of the thin sections and the possibility to combine fluid inclusion studies with microfossil studies lead to a wide range of advantages over ordinary thin sections. This includes the study of morphology, internal microstructures, colonies, association with the substrate that microfossils are attached to and geological and environmental context in which the microfossil once lived. When meeting the criteria of microfossil recognition the advantages of doubly polished thin sections are substantial and can be crucial in distinguishing between biogenic microfossils and abiotically formed abiomorphs
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