HoloSpec ƒ/1.8i
Holographic Imaging Spectrograph
The HoloSpec™ ƒ/1.8i holographic imaging spectrograph includes an integrated pre-filter section and provides extremely high throughput. The aperture ratio of ƒ/1.8 provides five- to twenty-times greater collection angle than spectrographs operating at ƒ/4 to ƒ/8.
The HoloSpec™ ƒ/1.8i is the ideal spectrograph for Raman spectroscopy and other laser spectroscopy applications. It includes a state-of-the-art holographic SuperNotch-Plus™ filter, which attenuates Rayleigh scatter by over six orders of magnitude, allows collection of data at Stokes shifts as low as 50 cm-1, and allows simultaneous collection of both Stokes and anti-Stokes data.
The HoloSpec™ ƒ/1.8i is the ideal spectrograph for Raman spectroscopy and other laser spectroscopy applications. It includes a state-of-the-art holographic SuperNotch-Plus™ filter, which attenuates Rayleigh scatter by over six orders of magnitude, allows collection of data at Stokes shifts as low as 50 cm-1, and allows simultaneous collection of both Stokes and anti-Stokes data.
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The HoloSpec™ holographic imaging spectrograph is based on Kaiser's award-winning axial transmissive spectrograph configuration. This configuration is based on holographic optical elements (HOEs) that are the result of a decade of development of HOEs for high-performance military applications.
In the axial transmissive spectrograph, the volume-phase holographic (VPH™) transmission grating replaces the Czerny-Turner spectrograph's surface-relief reflection grating as the dispersive element, and axially symmetric, multi-element lenses replace the off-axis, typically toroidal mirrors as the collimating and focusing elements. The VPH grating, recorded in dichromated gelatin, achieves high diffraction efficiency (typically 80% for unpolarized light) and high spatial frequency, while allowing a 90° fold angle, coupled with short-focal-length lenses. This results in a compact spectrograph with linear dispersion similar to that typically achieved with 1/4- to 1/2-meter Czerny-Turner spectrographs. The imaging design allows for multichannel or line imaging applications with no modification to the basic spectrograph.
In the axial transmissive spectrograph, the volume-phase holographic (VPH™) transmission grating replaces the Czerny-Turner spectrograph's surface-relief reflection grating as the dispersive element, and axially symmetric, multi-element lenses replace the off-axis, typically toroidal mirrors as the collimating and focusing elements. The VPH grating, recorded in dichromated gelatin, achieves high diffraction efficiency (typically 80% for unpolarized light) and high spatial frequency, while allowing a 90° fold angle, coupled with short-focal-length lenses. This results in a compact spectrograph with linear dispersion similar to that typically achieved with 1/4- to 1/2-meter Czerny-Turner spectrographs. The imaging design allows for multichannel or line imaging applications with no modification to the basic spectrograph.
Key Advantages of HoloSpec™ Spectrograph over Czerny-Turner Spectrographs
The axial-transmissive design of the HoloSpec spectrograph results in the following advantages over traditional Czerny-Turner spectrographs:
High Spatial Resolution
The optics employed in the HoloSpec™ spectrograph achieve thorough aberration correction across a large field along both the slit axis and the wavelength axis. This feature makes the HoloSpec™ spectrograph ideal for applications involving one-dimensional spectral imaging or simultaneous monitoring of many different spectra.
Unsurpassed Image Quality
The axial-transmissive design of the HoloSpec spectrograph results in the following advantages over traditional Czerny-Turner spectrographs:
High Spatial Resolution
The optics employed in the HoloSpec™ spectrograph achieve thorough aberration correction across a large field along both the slit axis and the wavelength axis. This feature makes the HoloSpec™ spectrograph ideal for applications involving one-dimensional spectral imaging or simultaneous monitoring of many different spectra.
Unsurpassed Image Quality
Image Data graphically illustrating the superior image quality acheivable by the HoloSpec ƒ/1.8i over the entire area of a commonly used CCD camera.
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Graphs are image cross-sections of a 250 line/inch Ronchi ruling taken at the edge of a 26 mm x 6.7 mm CCD having 23 micron pixels, illuminated at 543.5 nm.
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High Throughput
The HoloSpec™ spectrograph operate at aperture ratios as fast as ƒ/1.8, providing several times the light throughput of even the fastest Czerny-Turner spectrographs.
Compact
The footprint of the HoloSpec™ spectrograph is less than one-half or one-quarter that of typical quarter-meter or half-meter Czerny-Turner spectrographs.
Robust
The axial-transmissive configuration of the HoloSpec spectrograph, which uses no moving optics, provides a robust package with stable calibration ideal for process environments. The HoloSpec™ spectrograph is mountable in any orientation.
Easy to Use
The HoloSpec™ spectrograph include adjustments controlling focus and camera tilt, and mounts designed to facilitate switching among different input sources, gratings, and slits.
Spectral Range
The HoloSpec™ spectrograph can operate over the spectral range 425-nm to 900-nm when equipped with the appropriate gratings.
Gratings for Different Spectral Coverage
Gratings to provide spectral windows with widths of 75 to 400 nm on a 26-nm detector are available. Gratings are provided on pre-aligned base plates that can be easily exchanged.
The HoloSpec™ spectrograph operate at aperture ratios as fast as ƒ/1.8, providing several times the light throughput of even the fastest Czerny-Turner spectrographs.
Compact
The footprint of the HoloSpec™ spectrograph is less than one-half or one-quarter that of typical quarter-meter or half-meter Czerny-Turner spectrographs.
Robust
The axial-transmissive configuration of the HoloSpec spectrograph, which uses no moving optics, provides a robust package with stable calibration ideal for process environments. The HoloSpec™ spectrograph is mountable in any orientation.
Easy to Use
The HoloSpec™ spectrograph include adjustments controlling focus and camera tilt, and mounts designed to facilitate switching among different input sources, gratings, and slits.
Spectral Range
The HoloSpec™ spectrograph can operate over the spectral range 425-nm to 900-nm when equipped with the appropriate gratings.
Gratings for Different Spectral Coverage
Gratings to provide spectral windows with widths of 75 to 400 nm on a 26-nm detector are available. Gratings are provided on pre-aligned base plates that can be easily exchanged.
HoloSpec™ Accessories
Various accessories are available for the HoloSpec™ spectrograph, including:
Various accessories are available for the HoloSpec™ spectrograph, including:
- Entrance Slits
Kaiser offers the following fixed width slits for the HoloSpec™. Slits are easily exchanged using a quick exchange mount .
- Broadband Gratings
The following Broadband gratings are available at our Ann Arbor facility. Kaiser designs and manufactures custom gratings.
- Raman Gratings
Kaiser offers the following gratings for Raman spectroscopy applications. Kaiser designs and manufactures custom gratings.
- High Dispersion Gratings
Kaiser Manufactures High Dispersion Gratings(HDGs) for Raman and plasma applications. A single HDG can cover up to 1000 cm-1 using 532 nm excitation and a 1024 x 256 (26 micron pixel) CCD chip. Coverage is exciation wavelength dependant and each grating is specific for a single excitation wavelength. A 532 nm HDG yields 1000 cm-1 of spectral coverage. At 785 nm HDG grating yields 700 cm-1 of spectral coverage. The center wavelength of the HDG may be selected by the cutomer. The customer can specify either the center wavelength of the HDG grating or the approximate spectral coverage.
- Various input adapters
Kaiser offers a number of standard input adapters.
