Astronomical imaging can be broadly divided into two categories: (1) steady-state imaging, in which long exposures are required to capture ultra-low-light-level objects, and (2) time-resolved photometry, in which integration times range from milliseconds to a few seconds. While slow-scan, back-illuminated CCD cameras generally serve steady-state applications well, EMCCD cameras enable faster time-resolved applications such as adaptive optics and lucky imaging.
Adaptive optics: Under ideal conditions, the resolution of an optical system should only be limited by the diffraction of the light waves and the diameter of the lens system. However, due to turbulence in the atmosphere, even the world’s best telescopes cannot achieve this level of performance. Adaptive optics (AO) systems provide a way to compensate for these errors. As a result, images with resolution approaching the diffraction limit are now possible.
AO systems use a fast waveguide sensor for measuring the wavefront error and a feedback system to provide a compensating signal to a deformable optic. The accuracy and speed of the entire system relies on the sensor’s ability to provide a fast frame rate at a high signal-to-noise ratio. For example, EMCCD cameras are now capable of providing >1000 fps with less than 1 e- rms read noise for this application.
Lucky imaging: EMCCD cameras also enable another technique that is popularly used to improve the optical resolution of telescopes, lucky imaging. As the name suggests, the technique uses a subset of images from a large sequence to reconstruct a sharper, more detailed image of the target. Several papers have been published with data revealing more sensitive orders of magnitude using EMCCD cameras operated in photon-counting mode.
State-of-the-art Princeton Instruments cameras are successfully utilized at high-tech telescopes around the world. Whether your application demands slow-scan imaging that requires hours of integration or you need to perform rapid, time-resolved photometry, we have the right solution. All of our cameras support Linux operating systems. Here are a few guideposts to facilitate your search for the optimal imaging instrument.
Cameras in our ProEM series offer proprietary eXcelon3 back-illuminated EMCCD technology for enhanced sensitivity and the lowest etaloning; deep cooling with a lifetime vacuum guarantee; back illumination and electron multiplication (EM) gain for single-photon sensitivity; absolute EM gain calibration; ultra-stable bias for long sequences; slow 100 kHz readout speed in traditional CCD mode for 3 e- rms read noise; and a GigE data interface for remote operation (distances more than 50 meters).
The PIXIS series offers eXcelon back-illuminated, deep-depletion CCD technology for enhanced sensitivity and the lowest etaloning; deep cooling with a lifetime vacuum guarantee; read noise as low as 2.5 e- rms; UV-enhanced, back-illuminated CCDs; large 27.5 x 27.5 mm field-of-view CCDs; and true 16-bit dynamic range to capture both dim and bright areas in the same image.
Our NIRvana:640 features a 640 x 512 InGaAs detector with sensitivity from 0.8 µm to 1.7 µm, cooled to –85°C for low dark current. This camera provides excellent linearity and stability for quantitative imaging in the NIR II / SWIR range.
Image of Andromeda galaxy, our nearest neighboring galaxy taken by PIXIS: 2048B, deep cooled, 2K x 2K format CCD camera. Imagecourtesy of Brian Oetiker, Sam Houston State University, USA
Ultra-High-Sensitivity, Deeply Cooled InGaAs Cameras for Ground-Based Astronomy in the NIR-II / SWIR
Ground-based observations in the J and H astronomical bands can be improved by utilizing scientific InGaAs cameras from Princeton Instruments.
Is There Really Cool Gas in the Middle of the Sun?
Researchers Judd Johnson and Shadia Habbal from the University of Hawaii used two PIXIS:1024BR cameras to observe the total solar eclipse on March 9, 2007 in Libya.
LightField 64-bit software - trial download
Download a 45-day free trial of Princeton Instruments' Revolutionary 64-bit data acquisition package for spectroscopy and imaging.
Ground breaking software to control your Princeton Instruments systems. Now with Windows 10 support. It's like nothing you have ever experienced!