Optical enhancement of photomultiplier sensitivity

Transmission and reflection light losses are reduced by introducing light into end-window of device at an angle large enough to normal so total internal reflection occurs at both photocathode-vacuum and window-air interfaces

Multilayer microwave windows for wideband gyro-amplifiers

This paper presents the design and measurement of a HE11 mode multilayer window for a W-band gyro-amplifier. The window acts to seal the vacuum inside the amplifier whilst coupling out microwave power with minimal reflection and absorption. The Gaussian-like HE11 mode is used in order to achieve the lowest reflection through the window. Operating over 90-100 GHz the simulated reflection of this window is better than -30 dB. The design, simulation and microwave measurement of the window is presented

Precision polarimetry with real-time mitigation of optical-window birefringence

Optical-window birefringence is frequently a major obstacle in experiments measuring changes in the polarization state of light traversing a sample under investigation. It can contribute a signal indistinguishable from that due to the sample and complicate the analysis. Here, we explore a method to measure and compensate for the birefringence of an optical window using the reflection from the last optical surface before the sample. We demonstrate that this arrangement can cancel out false signals due to the optical-window birefringence-induced ellipticity drift to about 1%, for the values of total ellipticity less than 0.25 rad

Spin-filtered and Spatially Distinguishable Crossed Andreev Reflection in a Silicene-Superconductor Junction

We theoretically investigate the quantum transports in a junction between a superconductor and a silicene nanoribbon, under the effect of a magnetic exchange field. We find that for a narrow nanoribbon of silicene, remarkable crossed Andreev reflection (with a fraction $>50\%$) can be induced in the energy window of the elastic cotunneling, by destroying some symmetries of the system. Since the energy responses of electrons to the exchange field are opposite for opposite spins, these transport channels can be well spin polarized. Moreover, due to the helicity conservation of the topological edge states, these three transport channels are spatially separated in three different locations of the device, making them experimentally distinguishable. This crossed Andreev reflection is a nonlocal quantum interference between opposite edges through evanescent modes. If two superconducting leads with different phases are connected to two edges of the silicene nanoribbon, the crossed Andreev reflection can present Josephson type oscillations, with a maximal fraction $\sim 100\%$.Comment: 8 pages, 7 figure

Andreev reflection between a normal metal and the FFLO superconductor

We consider a process of the Andreev reflection between a normal metal and the s-wave superconductor in the FFLO state. It is shown that the process takes place if the energy of the incoming electron is bound within the finite interval called the Andreev window. The position of the window determines the value of the non-zero total momentum of Cooper pairs and the value of the gap

GaAs-based Self-Aligned Stripe Superluminescent Diodes Processed Normal to the Cleaved Facet

We demonstrate GaAs-based superluminescent diodes (SLDs) incorporating a window-like back facet in a self-aligned stripe. SLDs are realised with low spectral modulation depth (SMD) at high power spectral density, without application of anti-reflection coatings. Such application of a window-like facet reduces effective facet reflectivity in a broadband manner. We demonstrate 30mW output power in a narrow bandwidth with only 5% SMD, outline the design criteria for high power and low SMD, and describe the deviation from a linear dependence of SMD on output power as a result of Joule heating in SLDs under continuous wave current injection. Furthermore, SLDs processed normal to the facet demonstrate output powers as high as 20mW, offering improvements in beam quality, ease of packaging and use of real estate. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

In vivo multi-parametric imaging of metastatic and non-metastatic breast cancer

A current issue in cancer therapy is the characterization of metastatic tumors, which can increase ease of treatment and patient trials. We present an in vivo study of metastatic (4T1) and non-metastatic (4T1-TWIST KO) breast tumor sister cell lines to understand their metabolic behavior, determine differences in two modes of imaging (reflection & transmission), and observe effect of breathing higher oxygen percentage on vascular hemoglobin oxygen saturation. After injection of 10,000 cells into mice dorsal window chambers, the glucose intake and hemoglobin oxygen saturation was measured using a fluorescent glucose analog (2-NBDG) and hyperspectral trans-illumination imaging from 520-620 nm at 10 nm intervals, respectively. The metastatic tumors exhibited increased oxygen saturation and decreased glucose metabolism than non-metastatic tumors. Reflection mode of imaging was unable to pick intricacies in tumor parameters, and increased inhalation of oxygen caused increase in hemoglobin oxygen saturation