Design and testing of a two-monochromator reference spectrofluorimeter for high-accuracy total radiance factor measurements

A two-monochromator reference spectrofluorimeter has been developed at the National Research Council of Canada in accordance with International Commission on Illumination and American Society for Testing and Materials colorimetry standards to permit high-accuracy total spectral radiance factor measurements of fluorescent materials. This fully automated instrument employs a xenon-arc light source, all-reflective optics, two grating monochromators with order-sorting filters, a cooled photomultiplier tube analyzing detector, and a calibrated silicon photodiode monitor detector. The instrument operating range is 250-1050 nm with a selectable bandpass (optimized for a 5-nm resolution), and the measurement geometry is 45 degrees annular illumination and 0 degrees viewing (45/0). We describe the instrument's design, testing, and verification procedures. Systematic errors that have been determined and corrected for include instrument polarization, beam nonuniformity, wavelength shifts, stray light, and system drift. The wavelength accuracy and reproducibility are estimated to better than +/-0.1 and +/-0.03 nm, respectively. The photometric short-term repeatability and long-term reproducibility are estimated to be better than +/-0.15% and +/-0.5%, respectively. The overall photometric accuracy is better than 1% of the value over a wide range of reflectances, and the reproducibility of the color specification of a fluorescent material is better than 0.25 DeltaE(ab) units.

Design of single-element laser-beam shape projectors

The design and fabrication of several single-element laser-beam projectors are described. These projectors take a Gaussian laser beam and expand it into a uniform intensity diverging shape, which can be either a single line, circle, cross, star, or a D. Each element consists of a single segmented surface designed so as to produce the required projected shape.

Ultraviolet-visible spectrograph optics: ODIN project

We describe one of the possible designs for the UV-visible spectrograph optics to be employed in the ODIN project. The spectrograph will be used in a future satellite mission for aeronomy observations and will image a column of atmosphere just above the Earth's surface onto a two-dimensional CCD array with the spatial and spectral content aligned orthogonal to one another.

Design of a single-element laser-beam uniform cross projector

A single optical element has been designed that takes a Gaussian laser beam and expands it into a uniform diverging cross. The design and fabrication of such an element are described.

Optical transfer function measurment facility for aerial survey cameras

The optical transfer function measurement facility developed at the National Research Council of Canada primarily for testing aerial survey cameras has been upgraded to perform the task in an appreciably more convenient manner. Modifications made to the facility, which is based on the line spread function technique, include the replacement of the cumbersome physical scanning mechanism and detector unit with a detector assembly comprising a relay lens and a linear photodiode array. While eliminating the need for physically scanning the line spread function, it did require a change of light source, a daylight filter, and a new computer software package. The new setup is described in this paper. Several aerial survey cameras have been evaluated with the system, and results are given for a fairly standard Zeiss camera.