Abstract:
The present invention relates to a method and apparatus for producing high signal to noise spectral measurements in optical detector arrays and in particular to uncooled linear CCD arrays. This is accomplished by providing a detector and a database of dark signal readings unique to that detector that is generally created at the time of manufacture and that can then be used to provide a value for the dark signal inherent to that detector that can be used to correct the measured signal. The detector also includes a means to measure its temperature so that the appropriate dark signal value can be subtracted from the measured signal. This is because the dark signal is a function of both the temperature and the exposure time.
Abstract:
A method and arrangement for activating a photoirradiable chemical such as hematoporphyrin derivative (HPD) particularly in vivo by use of pulsed radiation of the required frequency higher energy input with less damage surrounding tissue can be achieved.
Abstract:
This invention is for a broad spectrum apparatus that provides a substantially uniform spectral response from a spectrometer by introducing one or more elements whose combined response or correction factor is the inverse of that produced by the rest of the apparatus. The response of the elements can be formed either pre or post dispersion. In the case of pre-dispersion the correcting components may be optical components chosen from a full combination of optical filters, either purely transmissive or a combination of transmissive and reflective as in the case of dichroic mirrors, optical lenses with chromatic aberration, integrating spheres or other diffusers coated with material whose response is wavelength dependant. The post-dispersive application may involve a spatial filter or shaped aperture to partially block the more intense wavelengths. A particular attractive application may be a mask that is directly etched onto the surface of a CCD array detector. Post-dispersive applications may also include custom neutral density filters or variable neutral density filters.