pi isoplane

Changing the Way the World Sees Spectroscopy!

so lane

IsoPlaneIsoPlane

soPlane

www.princetoninstruments.com/isoplane2

so lane

IsoPlaneIsoPlane

soPlane

Inspired Innovation

Imagine a spectrograph that sharply focuses data at every wavelength, allows the unrestricted use of large-format detectors, and directs photons where they are supposed to go.

Imagine a spectrograph that overcomes the limitations of traditional Czerny-Turner designs by significantly improving upon the image quality and resolution afforded by toroidal mirrors.

Princeton Instruments IsoPlane™ – A Revolutionary Imaging Spectrograph

The spectroscopists and engineers at Princeton Instruments not only imagined it, they built it!

We invite you to see the truly remarkable results… the Princeton Instruments IsoPlane, a revolutionary, aberration-free imaging spectrograph!

26.593

17.802

20.176

4.938

Cou

rtesy

of

K. F

ujita

, Osa

ka U

nive

rsity

Patent Pending


The Name Says It All so lane

IsoPlaneIsoPlane

soPlane

The exclusive, state-of-the-art optical design utilized in Princeton Instruments’ IsoPlane imaging spectrograph means this revolutionary instrument provides a sharply focused image across the entire focal plane, as compared to the smeared image of the Czerny-Turner.

With the IsoPlane spectrograph more photons end up in the peak, increasing the height and effective signal-to-noise ratio (SNR), rather than in the wings, where they contribute to the background noise.

Czerny-Turner spectrograph

so lane

The Isoplanatic Patch The area of sky around a reference star over which high-resolution imaging is possible is called the isoplanatic patch.

If the sky coverage of an imaging technique is substantially less than 100%, it will generally vary in proportion with the area of the isoplanatic patch.

The diameter of the isoplanatic patch for an imaging technique has a substantial impact* on the applicability of that technique to astronomical imaging.

* http://www.mrao.cam.ac.uk/telescopes/coast/theses/rnt/node17.html

Why waste time acquiring data you can’t use?



Outstanding spatial resolution

Eliminating the field astigmatism and reducing coma means that spectral lines are equally sharp across the focal plane. Resolution and peak intensity are preserved over the entire 27 mm width of a CCD sensor.

Multichannel spectroscopy

Poor imaging in Czerny-Turner spectrographs results in crosstalk, reduced contrast ratio, and excess noise. The IsoPlane provides fiber images that are sharp and distinct, allowing 4x or more spectra to be resolved over the height of a CCD sensor.

Simple, intuitive focusing and alignment Optimum camera positioning is critical to acquiring high-quality spectral data. In conventional spectrographs, it is difficult to repeatably align a bulky camera. The IsoPlane moves the focus to a micrometer-controlled mirror mount, right where it should be.

Aberration-Free Imaging = Outstanding Performance

Kinematic mount with torque limiter ensures perfect alignment every time when changing grating turrets.

On-axis grating rotation takes full advantage of the IsoPlane’s f/4.6 aperture for all wavelengths.

Superior spectral resolution

Near diffraction-limited imaging means spectral lines are sharp, with intensity concentrated in the peak, not the wings. Linewidth reduction by 1/2 to 2/3 vs. conventional spectrographs improves spectral resolution by 2x to 3x, with double the peak height.

so lane

IsoPlaneIsoPlane

soPlane

so lane

IsoPlaneIsoPlane

soPlane


Missing… But Not Missed Spherical aberration, coma, and astigmatism are conspicuously absent from IsoPlane images!

Spherical aberration

Coma

By eliminating the blur, the IsoPlane focuses more of the light on a given pixel, significantly increasing the measured peak height as seen here.

435.0 435.2 435.4 435.6 435.8 436.0 436.2 436.4 436.6

Inte

nsity

(cou

nts)

Wavelength (nm)

0

5

10

15x103

Spherical aberration arises when mirrors or lenses are used to focus light to form an image.

This aberration appears as a diffuse symmetrical blur on an image. It limits both the spatial and spectral resolution of a spectrograph.

Coma occurs when mirrors are used to image a source off-axis. Coma appears as a comet-shaped tail on a focused image or spectral line (i.e., a spectral line is asymmetrically broadened). Coma limits the spectral resolution of a spectrograph at most wavelengths, as it can be eliminated at only a single grating angle.


so lane

IsoPlaneIsoPlane

soPlane

Note: Red peak height is only 44% of blue peak heightThe IsoPlane greatly reduces

coma, thus preserving spectral resolution at all wavelengths.


Missing… But Not Missed

Astigmatism

Astigmatism is caused by using lenses or mirrors to image a source off-axis and appears as vertical elongation of an image (i.e., the ‘bow-tie’ effect or the vertical distortion of a fiber image). Astigmatism limits both spectral and spatial resolution, deteriorating towards the edges of the focal plane in a Czerny-Turner spectrograph.


so lane

Astigmatism is completely eliminated in the IsoPlane.


Perfected Performance

Focal plane imageThe IsoPlane eliminates field astigmatism and greatly reduces coma, enabling crisp, detailed imaging across a 27 x 8 mm focal plane.

The IsoPlane yields near-Lorentzian spectral lines at the center of the focal plane. Czerny-Turner spectrographs deliver inferior line shapes.

Spectral lines at focal plane center

so lane


Czerny-Turner spectrograph so lane

IsoPlaneIsoPlane

soPlane


Binning The IsoPlane produces clear, distinct images that make it easy to separate multiple spectral channels through binning.

Perfected Performance

IsoPlane (top) – high fluence across the focal plane, all spots are the same size – vs. Czerny-Turner spectrograph (bottom)

Eliminating crosstalk While Czerny-Turner spectrographs suffer from excessive crosstalk between adjacent channels, the IsoPlane eliminates it. Two-dimensional focal plane array detectors can record multiple spectra simultaneously, yet conventional spectrographs are ill-equipped for the job. Astigmatism in Czerny-Turner spectrographs means that only a few separate vertically spaced fibers can be resolved over the width of the sensor.

Crosstalk comparison

Preserving intensity The IsoPlane produces sharp spectral lines of constant width and height across the focal plane, whereas Czerny-Turner spectrographs do not.

Preservation of intensity, horizontal cross-section

Binning a spectrum from an image, horizontal cross-section


so lane


so lane


so lane


Meet an IsoPlane Engineer

Milestones in Spectrograph Design1930s 1950s 1988 2012

Czerny-Turner design first described

Scanning monochromators commercially introduced

Acton Research* introduces the SpectraPro triple-grating, direct-drive monochromator/spectrograph

The Advent of the IsoPlane!

Q: Was the development of the IsoPlane motivated by your own frustration with inferior imaging spectrographs?

A: We at Princeton Instruments had been searching for methods to improve the imaging performance of the Czerny-Turner spectrograph for several years. It was only after reading a book on the aberration theory of the reflecting telescope that I happened upon the idea of the IsoPlane. I was truly motivated by the elegant treatment of image aberration in the Schmidt-Cassegrain telescope through the use of Seidel aberration theory. From this theory and some creativity, the IsoPlane SCT-320 was developed. It is named the Schmidt-Czerny-Turner (SCT) from the Schmidt-like corrector the instrument uses to help achieve its imaging performance.

Q: Do you think that spectroscopists had generally accepted that this type of spectrograph would never be invented?

A: I believe so. The commercial imaging Czerny-Turner spectrograph is roughly 30 years old and has seen little to no improvement in that time. I think many spectroscopists simply believed the design was fully mature and that no further discoveries were possible.

Q: Why has it taken so long for this product to be developed?

A: Seidel aberration theory is over 150 years old, and the Czerny-Turner spectrograph is about 80years old. I think the reason the IsoPlane took so long to be developed was because we were all looking in the wrong place for the answers. Astronomers have hundreds more years’ experience than spectroscopists, and have fully developed Seidel aberration theory to describe every variant of the telescope. Such history does not exist for the spectrograph. We are proud to play a role in creating history with the discovery of the IsoPlane!

1995

Acton Research releases the SpectraPro with toroidal mirrors for improved imaging for CCDs

An Interview with Dr. Jason McClure – Chief Scientist at Princeton Instruments and Inventor of the IsoPlane

* Now part of Princeton Instruments!


Primary Applications The IsoPlane is ideally suited for use in a wide range of applications, including:

• Multichannel spectroscopy• Microspectroscopy, including Raman spectroscopy, fluorescence, and photoluminescence• Laser-induced breakdown spectroscopy (LIBS) and similar high-resolution techniques• Fourier-domain spectroscopy • Biomedical imaging

Multichannel imaging with the IsoPlane (28 channels)

Courtesy of K. Fujita, Osaka University

Courtesy of K. Fujita, Osaka University

Stellar Software Support The IsoPlane is supported by LightField™ 4.2 from Princeton Instruments, a 64-bit data acquisition platform for spectroscopy and imaging. LightField combines complete control over Princeton Instruments’ spectrographs and cameras with easy-to-use tools for experimental setup, data acquisition, and post-processing. Both unique and revolutionary, LightField lets researchers realize the full potential of the new IsoPlane imaging spectrograph.

Contact Princeton Instruments for additional information.www.princetoninstruments.com | [email protected]

USA TOLL-FREE +1.877.474.2286 | USA +1.609.587.9797

Copyright © 2012 Princeton Instruments, Inc. All rights reserved. IsoPlane and LightField are trademarks of Princeton Instruments, Inc. All other brand

and product names are the trademarks or registered trademarks of their respective owners and manufacturers.

About Princeton InstrumentsDrawing daily upon a rich heritage that encompasses more than a half-century of spectroscopy expertise, Princeton Instruments designs and manufactures world-renowned monochromators and spectrographs, precision optical coatings, and high-performance light detection systems tailored for spectroscopy, imaging, industrial, and x-ray applications.

Key Princeton Instruments innovations include the first spectroscopy cameras to utilize photodiode arrays and CCDs, as well as the first high-performance, gated, ICCD camera for spectroscopy. The introduction of the IsoPlane imaging spectrograph continues this unrivaled tradition of excellence.

Hardware Compatibility The IsoPlane can be configured with a variety of Princeton Instruments CCD, EMCCD, ICCD, and InGaAs cameras. Contact your sales engineer for further details.

Please download the data sheet from www.princetoninstruments.com/isoplane for specifications and more information.

Rev A0

pi isoplane

Documents