Pyramidal Wavefront Sensor Demonstrator at INO

Abstract

Wavefront sensing is one of the key elements of an Adaptive Optics System. Although Shack-Hartmann WFS are the most commonly used whether for astronomical or biomedical applications, the high-sensitivity and large dynamic-range of the Pyramid-WFS (P-WFS) technology is promising and needs to be further investigated for proper justification in future Extremely Large Telescopes (ELT) applications. At INO, center for applied research in optics and technology transfer in Quebec City, Canada, we have recently set to develop a Pyramid wavefront sensor (P-WFS), an option for which no other research group in Canada had any experience. A first version had been built and tested in 2013 in collaboration with NRC-HIA Victoria. Here we present a second iteration of demonstrator with an extended spectral range, fast modulation capability and low-noise, fast-acquisition EMCCD sensor. The system has been designed with compactness and robustness in mind to allow on-sky testing at Mont Mégantic facility, in parallel with a ShackHartmann sensor so as to compare both options.

Real-time adaptive optics with pyramid wavefront sensors: part I. A theoretical analysis of the pyramid sensor model

“…It is gradually gaining more and more attention from the scientific community, especially in astronomical AO, due to its increased sensitivity, improved signal-to-noise ratio, robustness to spatial aliasing and adjustable spatial sampling compared to the other popular wavefront sensor choice-the Shack-Hartmann (SH) sensor. Several theoretical studies [8,18,19,32,42,54,55,61,[72][73][74]76] including numerical simulations and laboratory investigations with optical test benches [4,29,46,51,71,75] have confirmed the advantages of pyramid wavefront sensors while additionally promising surveys were operated on sky [20-22, 25, 28, 49, 50, 52].…”

Optical design of infrared pyramid wavefront sensor for the MMT

“…As a result, the use of PWFSs can provide higher Strehl ratios, larger sky coverage, and higher contrast imaging capability. Some teams have already developed different types of PWFSs to test the behaviors and characteristics of PWFS [4][5][6][7] , however, there have not been detailed studies of the PWFS in the short-wave infrared (0.85-1.8 µm). The benefits can be substantial where infrared PWFS can increase sky coverage and observe highly obscured regions within our galaxy.…”