Two photon microscopy has found one of its main applications in the study of deep brain regions thanks to its intrinsic optical sectioning and deep penetration capabilities. One of the main limitations of deep 3D imaging is the arise of aberrations that can be reduced if not totally corrected using Adaptive Optics (AO). In this work we present the result of using a tunable acoustic gradient lens in combination with a multi actuator deformable lens placed in the back aperture pupil of the objective lens to correct for the sample aberrations.
In this presentation we show a method capable of measuring and correcting field dependent aberration in a microscope setup without a dedicated wavefront sensor using a pupil conjugated deformable lenses in combination with anisoplanatic deconvolution.
Laser beam distribution system (LBDS) is an important component at any high-power laser facility. Being a system of mirrors, lenses, and windows, the LBDS can significantly contribute to the laser beam quality degradation at target location. Phase correcting methods are among the few instruments allowing efficient control over the laser spot quality at the application site. We present a simpler solution utilizing only a PSF camera at every site. The PSF optimization is a sensorless modal correction algorithm, where each Legendre polynomial is scanned by the deformable mirror to find the best shape that maximize the PSF sharpness metric.
In this presentation we show Monte Carlo computer simulations of a satellite to ground optical channel, both in downlink and uplink, and analyze the importance of an Adaptive Optics (AO) system in mitigating atmospheric turbulence effects. Finally, the results of the numerical model will be compared with results from analytical models.
Long distance imaging and free space optical communications are largely affected by atmospheric turbulence. To attenuate turbulence effects, Adaptive Optics (AO) has been the main answer and, in the case of large FOV Multi Conjugate AO (MCAO) using two deformable mirrors (DM) has been proven to be an effective solution. We present a study and some preliminary results on the use of a stack of Adaptive Lenses (AL) in a MCAO setup with the main advantage of compactness end easiness of installation.
Free-space optical communication systems always require a precise focusing on the receiver to maximize the fiber coupling efficiency. Unfortunately, atmospheric turbulence causes scintillation at the receiver. Ground to ground receivers over short distances (up to 500m) have usually small aperture (about 50mm). In this case the main aberration is tip/tilt and its correction is of fundamental importance for high bandwidth data transmission. We present a new concept of Fast Steering Prism (FSP) for the correction of tilt, suitable for optical communication and optical tracking. The system consists in the use of a novel design of a tunable prism with a variable angle based on the usage of piezoelectric actuators. A system with a FSP has the advantage to be more compact and simpler with respect to the one with a fast-steering mirror. The entire setup has been tested in a 200m outdoor transmission with promising results.
Free-space optical communication systems always require a precise focusing on the receiver to maximize the fiber coupling efficiency. Unfortunately, atmospheric turbulence causes scintillation at the receiver. Ground to ground receivers over short distances (up to 500m) have usually small aperture (about 50mm). In this case the main aberration is tip/tilt and its correction is of fundamental importance for high bandwidth data transmission.
We present a new concept of Fast Steering Prism (FSP) for the correction of tilt, suitable for optical communication and optical tracking. The system consists in the use of a novel design of a tunable prism with a variable angle based on the usage of piezoelectric actuators. A system with a FSP has the advantage to be more compact and simpler with respect to the one with a fast-steering mirror. The entire setup has been tested in a 200m outdoor transmission with promising results.
Long distance imaging and free space optical communications are largely affected by atmospheric turbulence. To attenuate turbulence effects, Adaptive Optics (AO) has been the main answer and, in the case of large FOV Multi Conjugate AO (MCAO) using two deformable mirrors (DM) has been proven to be an effective solution. We present a study and some preliminary results on the use of a stack of Adaptive Lenses (AL) in a MCAO setup with the main advantage of compactness end easiness of installation.
We present a microscopy method capable of measuring aberrations in all the poits of the field of view and to correct for the field-dependent aberrations in a closed loop multi conjugated AO system using two deformable lenses and no wavefront sensor.
Optical quality in microscopy has reached a point where it is only limited by aberrations arising from sample inhomogeneities or refractive index mismatch in the focusing path. In this scenario adaptive optics is playing an increasingly important role. Most common microscopy AO setups rely on sensor-less algorithms and are designed to optimize only for one field. We present a method capable of measuring aberrations in every point on the field-of-view. This combined with the use of two deformable lenses permits to correct for field dependent aberrations in a closed loop MCAO system with virtually no changes in the microscopy setup.
The Sodium Laser Guide Star (Na-LGS) on the sky is not point-like, rather cigar-like when launched from the side of a large (or extremely large) telescope. The Na-LGS’s 3D nature gave birth to the idea of a new pupil-plane wavefront sensor that can be deployed in a similar 3D manner - the Ingot Wavefront Sensor (I-WFS). The design of the I-WFS has developed over the last two years, and currently, the ingot prism has 3-faces, creating three pupils. Wavefront sensing can be done using these three pupils themselves as the signals or the slopes generated by the pupils. At the INAF-Padova laboratory, we have realized a test-bench simulating the ELT∗ characteristics to test the I-WFS characteristics and an alignment procedure. We use simulations and lab data to compare, learn, and define a robust alignment procedure. Eventually, we expect to have an entirely automatized alignment procedure using the optical feedback from the I-WFS. In this article, we report the comparison between the laboratory data and the simulations representing (1) the sensitivity measurements of ingot prism misalignment for each degree of freedom with respect to its ideal, aligned position, and (2) the response of the I-WFS to known aberrations using a deformable lens. The final goal is the definition and description of the procedure to align the I-WFS.
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