仪器简介：
Optic arrangements using Echelle gratings are particularly suited for
 this task. They achieve an extremely high theoretical resolution 
capability by the diffraction of the light in a multitude of high 
interference orders. In the ELIAS, a 360 mm wide Echelle grating 
within a Littrow arrangement can be used alternatively in a double 
or single pass. This makes it possible, through motor-controlled 
software, to work either with an extremely resolving capability for 
profile characterization or with a reduced resolving capability but 
larger spectral range and higher sensitivity. The system is compact 
and extremely thermally and mechanically stable. The complete 
motorization allows a very simple operation as well as the automatic
 focusing and positioning of the spectrum on the detector. By 
exclusively applying reflection optics with broad-band UV layers,
 chromatic aberrations are avoided and there are no limitations in 
choosing the measurement wavelengths. The coupling into the 
spectrometer is realized via a SMA fiber coupling or optionally via
 pure reflection transfer optics

技术参数：
Specifications ELIAS - Series
- Detector: CCD line-array detector ELIAS I: 1024 pixels; ELIAS II: 2048 pixels
- Dynamic range: 16 Bit AD-conversion, effectively approx. 33000:1
- Signal-to-noise ratio: at level 40000 ELIAS I better than 3000 / 35 dB
ELIAS II better than 10000 / 40 dB
- Exposure time min: ELIAS I: 18 ms; ELIAS II: 2 ms
- Integrated mechanical shutter
- Coupling via fiber, except for ELIAS-VUV (mirror optics)
- Wavelength calibration by integrated mercury lamp (253.652 nm)
- Absolute accuracy when calibrating with the internal Hg lamp better than +/- 5 pm
- Rel. pixel dispersion error depending on the wavelength, for 193 nm double pass 0.2 fm
- Industrial PC with Windows 2000
- Software: Sophi; LabView driver optional
- Measurements ELIAS Standard: (L x B x H) 1400 x 500 x 1300 (mm3)


主要特点：
1.It is used for the highly resolving spectral measurement of
emission and absorption lines, particularly of laser lines
2.offer radiation sources with the lowest spectral width
3.dynamic of the intensity detection of up to 4 orders
4.The line profiles can be detected simultaneously within their
spectral vicinity by means of a CCD
5.Because of their chromatic aberrations, the refraction objectives
in the wafer steppers require an extremely high spectral purity of
the radiation sources