Graded multilayer mirrors for the carbon window Schwarzschild objective

The paper deals with the recent progress in fabrication of the graded multilayer mirrors to be used in a 21X Schwarzschild objective operating at the wavelengths about 4.5 nm ("carbon window" region). The graded Co/C reflective multilayer coatings were fabricated using DC-magnetron sputtering. Mask-assisted deposition was used to create the required radial variation of the multilayer period. Accuracy of the multilayer's parameter measurements and quality of nm-scale layer deposition were improved significantly with application of a number of new methods and approaches. The soft X-ray measurements were conducted at the ALS 6.3.2 beamline to quantify the graded periods on concave and convex mirrors of the Schwarzschild objective. They demonstrated that the reflectivity curves were adjusted with the accuracy of about 0.008 nm (0.3%) over the entire mirror surfaces. The total throughput of the objective with full working aperture (NA ~ 0.2) is estimated to be as high as 0.25%.

[1]  B. L. Henke,et al.  X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E = 50-30,000 eV, Z = 1-92 , 1993 .

[2]  I. A. Artyukov,et al.  X-ray microscopy in the carbon window region , 2004 .

[3]  D. Attwood.  Soft X-Rays and Extreme Ultraviolet Radiation , 1999 .

[4]  Igor A. Artyukov,et al.  Carbon window soft x-ray imaging using multilayer optics , 2005, SPIE Optics + Photonics.

[5]  E. Gullikson,et al.  Soft X-ray reflectivity and structure evaluation of CoCr/C multilayer X-ray mirrors for spectral region around 6 nm , 2001 .

[6]  Hans M. Hertz,et al.  Design and performance of a laser-plasma-based compact soft x-ray microscope , 2002 .

[7]  Milind Rajadhyaksha,et al.  Skin imaging with reflectance confocal microscopy. , 2008, Seminars in cutaneous medicine and surgery.

[8]  Anatoly I. Fedorenko,et al.  LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Reflective soft x-ray microscope for the investigation of objects illuminated by laser-plasma radiation , 1995 .

[9]  J. Kortright,et al.  Masked deposition techniques for achieving multilayer period variations required for short-wavelength (68-A) soft-x-ray imaging optics. , 1993, Applied optics.

[10]  M. Agnello,et al.  Confocal microscopy study of the distribution, content and activity of mitochondria during Paracentrotus lividus development , 2007, Journal of microscopy.

[11]  Chris Jacobsen,et al.  Carbon edge XANES spectroscopy of amino acids and peptides , 1997 .

[12]  E. Gullikson,et al.  High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50–1300 eV energy region , 1998 .

[13]  Arthur B. C. Walker,et al.  Development of the water-window imaging x-ray microscope , 1991, Optics & Photonics.

[14]  C S Menoni,et al.  Nanometer-scale ablation with a table-top soft x-ray laser. , 2006, Optics letters.

[15]  D Attwood,et al.  Reflection mode imaging with nanoscale resolution using a compact extreme ultraviolet laser. , 2005, Optics express.

[16]  S W Hell,et al.  Ca2+ fluorescence imaging with pico- and femtosecond two-photon excitation: signal and photodamage. , 1999, Biophysical journal.

[17]  Jacobsen,et al.  Soft X‐ray spectroscopy from image sequences with sub‐100 nm spatial resolution , 2000, Journal of microscopy.

[18]  Gerry McDermott,et al.  Quantitative 3-D imaging of eukaryotic cells using soft X-ray tomography. , 2008, Journal of structural biology.

[19]  C. D. Wang,et al.  Structural stability of heat-treated Co/C soft X-ray multilayers fabricated by dual-facing-target sputtering , 1996 .

[20]  B. Niemann,et al.  X-ray microscopy with synchrotron radiation at the electron storage ring BESSY in Berlin , 1986 .

[21]  O. Gileadi,et al.  Electron Microscopy of Wet Tissues: A Case Study in Renal Pathology , 2004, Toxicologic pathology.

[22]  H. Nagata,et al.  Schwarzschild microscope for carbon Kα radiation. , 1993, Applied optics.

[23]  I. A. Artyukov,et al.  Advances in short-wavelength x-ray multilayer optics: toward high-throughput multimirror systems for the wavelengths <10 nm , 2007, SPIE Optical Engineering + Applications.

[24]  Soft-x-ray projection lithography experiments using Schwarzschild imaging optics. , 1993, Applied optics.