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We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope's MTF, tests with the BPRML sample can be used to fine tune the instrument's focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters. [ABSTRACT FROM AUTHOR]

A robust operator independent measurement of electron beam sizes in two coordinates is demonstrated by using beam metrology (BEAMETR) technique. This method involves software associated with a specially designed pattern sample. The fabrication of this sample was done using 100 keV electron beam lithography and lift-off of metal. A proximity correction was applied to improve pattern quality. The minimum feature size of the fabricated BEAMETR patterns was 20 nm; this allowed for the measuring of beam size down to 2 nm. Beam size and shape measurements were done using three scanning electron microscopes; their operating conditions (voltage, aperture, and astigmatism) were varied. Repeatability and test pattern dependence were also studied, which demonstrated a good consistency of the results. [ABSTRACT FROM AUTHOR]

A concept of digital optical spectrometer-on-chip is proposed and results of their fabrication and characterization are reported. The devices are based on computer-designed digital planar holograms which involves millions of lines specifically located and oriented in order to direct output light into designed focal points according to the wavelength. Spectrometers were fabricated on silicon dioxide and hafnium dioxide planar waveguides using electron beam lithography and dry etching. Optical performances of devices with up to 1000 channels for a central wavelength of 660 nm are reported. [ABSTRACT FROM AUTHOR]

The authors report absorption measurements on low concentration analytes using a microfluidic dye laser. The laser cavity is made of two gold mirrors coated on the end faces of two optical fibers inserted in a chip. Rhodamine 6G dye molecules dissolved in ethanol are used for laser amplification and absorption measurements are done with methylene blue dye solutions. When optically pumped with a frequency doubled Nd:YAG laser at 532 nm wavelength, the device shows a laser output emission at 565 nm and a high sensitivity of the lasing output to the losses in the cavity, in good agreement with the results of numerical calculations. [ABSTRACT FROM AUTHOR]