ARYELLE 400

Powerful high-resolution echelle spectrometer for the material and elemental analysis with LIBS and Raman spectroscopy in industry and science.

• High resolution and sensitivity
• Large wavelength range
• Simultaneous detection
• High imaging quality

Principle of operation

ARYELLE 400 is an echelle spectrometer that can generate spectra of relatively arbitrary dimension with high wavelength stability, spectral resolution and radiation throughput. It is used for the highly resolving spectral measurement of plasma emission lines. The lines can be detected simultaneously within a large spectral wavelength range by using a CCD or ICCD camera. LTB also provides complete systems including laser system, beam guidance and sample chamber.

Application fields of the ARYELLE spectrometers are the material and elemental analysis by means of plasma and Raman spectroscopy. Due to its compact design it is well suited for the process control, e.g. in the steel, glass and ceramics industry, the geology, gemmology and environmental analysis.

Optic arrangements using echelle gratings are particularly suited for emission spectrometry. They achieve extremely high spectral resolution and broad-band efficiency by the diffraction of the light in a multitude of high interference orders. A prism separates the echelle orders in cross dispersion direction generating the typical two-dimensional image of the echelle spectrum on the detector. To effectively use the resolution capability of the echelle grating and to resolve the lines according to the typical pixel width of the array detector, high imaging quality is guaranteed by applying a new patented optical layout.

The ARYELLE can be freely dimensioned regarding the parameters of the entrance slit, the echelle grating, the prism and the imaging optics. This makes it possible to adapt the wavelength range and the spectral resolution to nearly all applications. For each the VUV-UV range of 175 - 330 nm and the UV-VIS-NIR range of 330 - 850 nm spectrometers are available.

For measuring wide-range LIBS spectra, the

ARYELLE 400-Butterfly Spectrometer

has been developed. It consists in principle of two ARYELLE spectrographs, the spectra of which illuminate one shared detector. Thus the double spectrograph ARYELLE-Butterfly provides the opportunity to measure spectra with an enormous variability. Separating the spectral range and using only one detector provides a cost-efficient solution to use the detector most efficiently, to shorten the read-out time and to flexibly arrange the illumination times.

The optical and mechanical concept result in a compact, thermally and mechanically extremely stable set-up. It has an automatic user-independent calibration. By exclusively applying reflection optics with broad-band UV coatings, chromatic aberrations are avoided and there are no limitations in choosing the measurement wavelengths. The light coupling into the spectrometer is realized via a SMA fibre coupling for the UV-VIS-NIR range or via pure reflection transfer optics for the VUV range.

LTB Lasertechnik Berlin offers its ARYELLE-Butterfly spectrometer either with a CCD with chopper or with an ICCD. Applying a CCD in combination with a chopper instead of an ICCD as detector allows a better sampling of the lines as a result of the higher spatial resolution of the detector. Compared to the ICCD, an approximately 10 times better signal-to-noise ratio is achieved due to the lower dark noise. Moreover, the price is lower. Advantages of the ICCD are the better time resolution and the higher controlling variability. A powerful cooling of the detector system reduces the dark noise of the detector and improves the signal-to-noise ratio significantly. The limit of detection (LOD) depends on the sample matrix and the element to be detected; in general LODs in the range of 10-500 ppm can be achieved for the majority of elements in solid state matrices. The accuracy is better than 10 % of the measured value.

Software

The controlling and evaluation software Sophi for ARYELLE controls all spectrometer and detector functions. After assigning the raw data to the corresponding wavelengths, all lines of the spectrum are automatically analyzed with an integrated data base and if possible assigned to the corresponding elements and specified. Quantitative analysis algorithms are integrated as well. For a quantitative evaluation, a calibration with comparable samples is necessary.