28 research outputs found
Soliton back-action evading measurement using spectral filtering
We report on a back-action evading (BAE) measurement of the photon number of
fiber optical solitons operating in the quantum regime. We employ a novel
detection scheme based on spectral filtering of colliding optical solitons. The
measurements of the BAE criteria demonstrate significant quantum state
preparation and transfer of the input signal to the signal and probe outputs
exiting the apparatus, displaying the quantum-nondemolition (QND) behavior of
the experiment.Comment: 5 pages, 5 figure
Insertion of CdSe quantumdots in ZnSe nanowires : MBE growth and microstructure analysis
ZnSe nanowire growth has been successfully achieved on ZnSe (100) and (111)B
buffer layers deposited on GaAs substrates. Cubic [100] oriented ZnSe nanowires
or [0001] oriented hexagonal NWs are obtained on (100) substrates while [111]
oriented cubic mixed with [0001] oriented hexagonal regions are obtained on
(111)B substrates. Most of the NWs are perpendicular to the surface in the last
case. CdSe quantum dots were successfully incorporated in the ZnSe NWs as
demonstrated by transmission electron microscopy, energy filtered TEM and high
angle annular dark field scanning TEM measurements
Critical Petermann K factor for intensity noise squeezing
We investigate the impact of the Petermann-excess-noise factor K >= 1 on the possibility of intensity noise squeezing of laser light below the standard quantum limit. Using an N-mode model, we show that squeezing is limited to a floor level of 2(K-1) times the shot noise limit. Thus, even a modest Petermann factor significantly impedes squeezing, which becomes impossible when K >= 1.5. This appears as a serious limitation for obtaining sub-shot-noise light from practical semiconductor lasers. We present experimental evidence for our theory
Photon Correlations and Cross-Correlations from a Single CdTe/ZnTe Quantum Dot
We report correlation and cross-correlation continuous wave measurements in II-VI quantum dots grown by molecular beam epitaxy. Combination of spectral selection, saturation measurements and good temporal resolution allowed us to see an antibunching effect on photons from radiative recombination of excitons in a single CdTe/ZnTe quantum dot, as well as cross-correlation within the biexciton (X)-exciton (X) radiative cascade from the same dot. We discuss the results of our experiments in terms of a model of excitonic multitransitions
Management of non-functional pancreatic neuroendocrine tumors by endoscopic ultrasound-guided radiofrequency ablation: Retrospective study in two tertiary centers.
Recently, there has been growing interest in investigating endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) for the management of small non-functional pancreatic neuroendocrine tumors (nf pNETs).
A bicentric retrospective study was performed that included patients with histologically confirmed nf pNETs who were consecutively treated by EUS-RFA between December 2015 and March 2021 at two tertiary referral centers.
In 27 patients (mean age 65.0 years, 52% male), EUS-RFA was successfully performed. All patients had sporadic G1 lesions (mean size 14.0 ± 4.6 mm, 7% uncinated process, 22% head, 11% body, 19% body/tail junction, and 41% tail). Overall, 9/27 lesions (33%) were cystic. The mean hospital stay was 3.2 days. Complete treatment response was confirmed in 25/27 patients (93%) on cross-sectional imaging (mean follow-up 15.7 ± 12.2 months, range 2-41 months). Two patients had two EUS-RFA sessions until complete necrosis was observed. Periprocedural acute pancreatitis occurred in 4/27 (14.8%), three of them were treated by endoscopic cystogastrostomy (11.1%). One patient underwent secondary surgery. The histopathology of the resected specimen revealed 3 mm of residual tumor tissue.
EUS-RFA seems to be a promising treatment strategy for the management of small nf pNETs with excellent efficacy. Further evidence focusing on long-term survival, safety profile and recurrence is needed