Modal analysis using photonic lanterns coupled to arrays of waveguides.

We present a new concept of an integrated optics component capable of measuring the complex amplitudes of the modes at the tip of a multimode waveguide. The device uses a photonic lantern to split the optical power carried by an N-modes waveguide among a collection of single-mode waveguides that excite a periodic array of at least N2single-mode evanescently-coupled waveguides. The power detected at each output of the array is a linear combination of the products of the modal amplitudes-a relation that can, under suitable conditions, be inverted allowing the derivation of the amplitudes and relative phases of the modal mixture at the input. The expected performance of the device is discussed and its application to the real-time measurement of modal instability in high power fiber lasers is proposed.

Prevalence of malnutrition in patients at first medical oncology visit: the PreMiO study.

BACKGROUND: In cancer patients, malnutrition is associated with treatment toxicity, complications, reduced physical functioning, and decreased survival. The Prevalence of Malnutrition in Oncology (PreMiO) study identified malnutrition or its risk among cancer patients making their first medical oncology visit. Innovatively, oncologists, not nutritionists, evaluated the nutritional status of the patients in this study. METHODS: PreMiO was a prospective, observational study conducted at 22 medical oncology centers across Italy. For inclusion, adult patients (>18 years) had a solid tumor diagnosis, were treatment-naive, and had a life expectancy >3 months. Malnutrition was identified by the Mini Nutritional Assessment (MNA), appetite status with a visual analog scale (VAS), and appetite loss with a modified version of Anorexia-Cachexia Subscale (AC/S-12) of the Functional Assessment of Anorexia-Cachexia Therapy (FAACT). FINDINGS: Of patients enrolled (N=1,952), 51% had nutritional impairment; 9% were overtly malnourished, and 43% were at risk for malnutrition. Severity of malnutrition was positively correlated with the stage of cancer. Over 40% of patients were experiencing anorexia, as reported in the VAS and FAACT questionnaire. During the prior six months, 64% of patients lost weight (1-10 kg). INTERPRETATION: Malnutrition, anorexia, and weight loss are common in cancer patients, even at their first visit to a medical oncology center.

Towards 3D-photonic, multi-telescope beam combiners for mid-infrared astrointerferometry.

In the past two decades high precision optical astronomical interferometry has benefited from the use of photonic technologies. Today, near-infrared interferometric instruments deliver high-resolution, hyperspectral images of astronomical objects and combine up to 4 independent telescopes at a time thanks to integrated optics (IO). Following the success of IO interferometry, several initiatives aim at developing components which could combine simultaneously more telescopes and extend their operation beyond the near-infrared bands. Here we report on the development of multi-telescope IO beam combiners for mid-infrared interferometry exploiting the three-dimensional (3D) structuring capabilities of ultrafast laser inscription. We characterise the capability of a 2-telescope and a 4-telescope beam combiner to retrieve the visibility amplitude and phase of monochromatic light fields at a wavelength of 3.39 µm. The combiner prototypes exploit different 3D architectures and are written with a femtosecond laser on substrates of Gallium Lanthanum Sulfide. Supporting numerical simulations of the performance of the beam combiners show that there is still room for improvement and indicate a roadmap for the development of future prototypes.

Ultrafast laser inscription in ZBLAN integrated optics chips for mid-IR beam combination in astronomical interferometry.

Astronomical interferometry is a unique technique that allows observation with angular resolutions on the milliarcsec scale by combining the light of several apertures hundreds of meters apart. The PIONIER and GRAVITY instruments at the Very Large Telescope Interferometer have demonstrated that silica-based integrated optics (IO) provide a small-scale and highly stable solution for the interferometric beam combination process. Yet, important science cases such as exoplanet hunting or the spectroscopic characterization of exoplanetary atmospheres are favorable for observation in the mid-IR, namely the atmospheric windows L and L' band (3-4 µm), a wavelength range that is not covered by conventional silica-based IO. Here, we propose laser-inscribed IO 2×2 couplers in ZBLAN and experimentally assess the critical properties of the component for broadband mid-IR interferometry. We measure the splitting ratio over the 2.5 to 5.0 µm range and find excellent broadband contrast over the L (3.1-3.6 µm) and L' (3.6 - 4.0 µm) bands. Furthermore, we quantify the dispersion properties of the coupler and find a phase variation as low as 0.02 rad across the L and L' band, respectively. By optimizing the NA of our injection beam, we measured a very high total throughput of 58% over the L band including Fresnel reflection and coupling losses. We also compare our findings to recent advances in mid-IR IO in GLS and discuss its advantages and disadvantages for the implementation in future mid-IR interferometers.

Real-time adaptive optics testbed to investigate point-ahead angle in pre-compensation of Earth-to-GEO optical communication.

We explore adaptive optics (AO) pre-compensation for optical communication between Earth and geostationary (GEO) satellites in a laboratory experiment. Thus, we built a rapid control prototyping breadboard with an adjustable point-ahead angle where downlink and uplink can operate both at 1064 nm and 1550 nm wavelength. With our real-time system, beam wander resulting from artificial turbulence was reduced such that the beam hits the satellite at least 66% of the time as compared to merely 3% without correction. A seven-fold increase of the average Strehl ratio to (28 ± 15)% at 18 µrad point-ahead angle leads to a considerable reduction of the calculated fading probability. These results make AO pre-compensation a viable technique to enhance Earth-to-GEO optical communication.

[Value-based cancer care. From traditional evidence-based decision making to balanced decision making within frameworks of shared values]. / La decisione oncologica basata sui valori Dal tradizionale processo decisionale oncologico evidence-based a scelte basate su valori bilanciati e condivisi.

Clinical decision making in oncology is based so far on the evidence of efficacy from high-quality clinical research. Data collection and analysis from experimental studies provide valuable insight into response rates and progression-free or overall survival. Data processing generates valuable information for medical professionals involved in cancer patient care, enabling them to make objective and unbiased choices. The increased attention of many scientific associations toward a more rational resource consumption in clinical decision making is mirrored in the Choosing Wisely campaign against the overuse or misuse of exams and procedures of little or no benefit for the patient. This cultural movement has been actively promoting care solutions based on the concept of "value". As a result, the value-based decision-making process for cancer care should not be dissociated from economic sustainability and from ethics of the affordability, also given the growing average cost of the most recent cancer drugs. In support of this orientation, the National Comprehensive Cancer Network (NCCN) has developed innovative and "complex" guidelines based on values, defined as "evidence blocks", with the aim of assisting the medical community in making overall sustainable choices.

Topical Application of a Galenical Formulation for the Management of Everolimus-Induced Mucositis in Patients with Metastatic Cancer: a Retrospective Study.

INTRODUCTION: Stomatitis is a common and potentially dose-limiting adverse event of the mammalian target of rapamycin (mTOR) inhibitor therapy. To minimize dose reductions or treatment delays that may affect therapeutic outcomes, management includes patient education, pain management strategies, and drug treatment. The aim of this study was to evaluate the effectiveness of a topically-applied galenical preparation to minimize the impact of everolimus-associated oral mucositis in patients with advanced cancer. METHODS: Patients receiving everolimus plus exemestane for advanced breast cancer or everolimus alone for advanced renal cancer were eligible for inclusion. All patients were advised on procedures to maintain good oral hygiene and directed to use a dexamethasone-containing galenical preparation at the first signs of mucositis. Questionnaires were administered at baseline, and after cycles one, two, and three to evaluate the presence, duration, and intensity of oral mucositis. RESULTS: Of the 19 patients included in the study (mean age 66 years; 16% male), mucositis developed in 10.5%, 47.4%, and 52.6% of patients after the first, second, and third cycles of everolimus, respectively. The median time to development of mucositis was 18.0 days, and the median time to mucositis resolution was 30.0 days. After the first, second, and third cycles of therapy, 5.3%, 10.5%, and 10.5% of patients required interruption of everolimus therapy; however, no dosage reductions for mucositis were necessary. CONCLUSIONS: Patient education and the provision of an effective galenical preparation can minimize the effect of mTOR inhibitor-related mucositis.

Interferometric nulling of four channels with integrated optics.

Nulling interferometry has been identified as a competitive technique for the detection of extrasolar planets. In its basic form, the technique consists of combining out-of-phase a single pair of telescopes to effectively null the light of a bright star and reveal the dim glow of the companion. However, in order to mitigate the effect of the stellar leaks through the interferometer, a broad angular central null is required. The hierarchical combination of several pairs of telescopes can accomplish this task. We have manufactured and tested with monochromatic light an integrated optics component, which combines a linear array of four telescopes in the nulling mode envisaged by Angel and Woolf [Astroph. J.475, 373-379 (1997).10.1086/apj.1997.475.issue-1ASJOAB0004-637X]. By simulating in the laboratory the motion of a star in the sky, we could measure the expected angular transmission of the four-telescope nuller. Moreover, the tests have demonstrated a broad nulling scaling as the fourth power of the baseline delay.

Targeted therapy in renal carcinoma: a case of long-term effect with complete control of toxicity.

Although advances in imaging techniques have allowed earlier diagnosis of renal cell carcinoma (RCC) in recent decades, one-third of patients who have undergone radical resection of organ-confined disease will eventually develop metastases. The treatment of metastatic RCC was revolutionized by the advent of targeted therapy with tyrosine kinase inhibitors. We have followed seven patients with metastatic RCC who were treated with first-line pazopanib at our center. The case of one of these patients is described here in detail. The patient was first diagnosed with RCC in 1999 and metastases were detected in 2006 and 2012. Treatment with pazopanib at the standard dose of 800 mg/day for 29 months led to a partial response that persisted over time. Side effects (hypertension and painful mucositis) were successfully managed with supportive care at our oral therapy clinic. Early management of adverse events using a multidisciplinary approach is paramount to the favorable outcome of treatment with pazopanib and other targeted agents.

Imaging cross-correlation FROG: measuring ultrashort, complex, spatiotemporal fields.

We present imaging cross-correlation frequency-resolved optical gating (ImXFROG), a new method for the spatiotemporal phase retrieval of ultrashort pulses. It is demonstrated that ImXFROG can measure phase and intensity of arbitrary, spatiotemporally distorted pulses with femtosecond resolution and up to 10(7) independent variables. ImXFROG is implemented as a plug-in upgrade to an existing correlator and used to demonstrate the reconstruction of highly complex, optical pulses with femtosecond features and massive spatiotemporal distortion.

Improvement of quality of life in third-line chemotherapy with lapatinib in a case of metastatic breast cancer.

We describe a case of a 72-year-old patient suffering from metastatic breast cancer. The disease had progressed slowly and was almost asymptomatic for a significant time. Toxicity, following third-line treatment with lapatinib, was not significant, and side effects were well controlled. The case is an excellent example of a chronic neoplastic disease in a patient who could be defined as "long-surviving".

3D-integrated optics component for astronomical spectro-interferometry.

We present the experimental characterization of a spectro-interferometry setup based on a laser-written three-dimensional integrated optics component. By exploiting the interferometric capability of a two-dimensional array of evanescently coupled waveguides, we measure the mutual coherence properties of three different polychromatic optical fields. Direct application of our discrete beam combiner (DBC) component is astronomical interferometry. The DBC can be scaled up to combine arbitrary large number of telescopes for the determination of coherence properties of astronomical targets. Besides applications to astronomy, the DBC can be also applied to optical integrated metrology system requiring nanometric position monitoring. The working principle, the experimental setup used, and the broadband performance of the DBC are presented.

Temporal switching induced by cascaded third order nonlinearity.

We investigate the impact of cascaded third harmonic generation and the intrinsic n4 material nonlinearity on the propagation of ultrashort pulses in noble-gas filled Kagome fibers. We show that the pressure tunability of the cascade allows for the implementation of temporal switching. We also investigate the relative strengths of both effects and show their ratio to be pressure tunable.

Higher-order Kerr effect and harmonic cascading in gases.

The higher-order Kerr effect (HOKE) has recently been advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth-order nonlinearity that is negative and significant. Higher-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths, cascading increases the HOKE saturation intensity, while for longer wavelengths cascading will decrease the HOKE saturation intensity.

Three-dimensional photonic component for multichannel coherence measurements.

We present the experimental results of a three-dimensional integrated photonic component designed for the simultaneous determination of mutual coherence properties of three light channels. Potential applications to astronomical optical interferometry are proposed and discussed.

Digital holography from shadowgraphic phase estimates.

We show experimentally that the recently proposed iterative shadowgraphic method can be applied to in-line digital holography, provided a suitable regularization step is introduced. We show that the method correctly solves the "twin-image" problem using just two samples of the intensity field scattered by a phase object. Field retrieval accuracy is significantly improved when compared to a reconstruction obtained with the defocusing variation algorithms.

Light bullets in waveguide arrays: spacetime-coupling, spectral symmetry breaking and superluminal decay [Invited].

We investigate the effects of the space-time coupling (STC) on the nonlinear formation and propagation of Light Bullets, spatiotemporal solitons in which dispersion and diffraction along all dimensions are balanced by nonlinearity, through periodic media with a weak transverse modulation of the refractive index, i.e. waveguide arrays. The STC arises from wavelength dependence of the strength of inter-waveguide coupling and can be tuned by variation of the array geometry. We show experimentally and numerically that the STC breaks the spectral symmetry of Light Bullets to a considerable degree and modifies their group velocity, leading to superluminal propagation when the Light Bullets decay.

Interferometric beam combination with discrete optics.

We explore the capabilities of discrete diffraction in phase retrieval problems and propose an innovative scheme exploiting a two-dimensional array of coupled waveguides to determine the phase and amplitude of the mutual correlation function between any pair of three telescopes of an astrointerferometer.

Accurate retrieval of pulse-splitting dynamics of a femtosecond filament in water by time-resolved shadowgraphy.

By means of a time-resolved, shadowgraphic method we observed directly the development of the pulse-splitting dynamics of a femtosecond laser pulse propagating in the filamentary regime in water. For the first time to our knowledge, the relative splitting velocity was measured. We compare the experimental data with numerical simulations. A possible scenario for the splitting event and evolution of the fragments is discussed.

Phase front retrieval by means of an iterative shadowgraphic method.

In this paper, we propose an iterative shadowgraphic method (ISM) as an interesting alternative to existing methods for self-referencing optical phase retrieval. Two defocused images of the intensity distribution of the light scattered by a weakly absorbing phase object were sufficient to retrieve the transverse phase distribution of the distorted illuminating beam. An algorithm was developed to correct for diffraction effects in phase maps retrieved with a simple shadowgraphic method. We provide a mathematical proof of the convergence of the algorithm to the true profile of the sought phase object. Several numerical tests were performed of the algorithm showing its capability of recovering the full details of the original phase distribution with increased resolution as compared with the simple shadowgraphic method. The convergence of the ISM was also compared numerically with that of a nonoptimized Gerchberg-Saxton-type algorithm and found to be faster and not affected by stagnation problems.