Abstract: A method and system for locally processing a predetermined microstructure formed on a substrate without causing undesirable changes in electrical or physical characteristics of the substrate or other structures formed on the substrate are provided. The method includes providing information based on a model of laser pulse interactions with the predetermined microstructure, the substrate and the other structures. At least one characteristic of at least one pulse is determined based on the information. A pulsed laser beam is generated including the at least one pulse. The method further includes irradiating the at least one pulse having the at least one determined characteristic into a spot on the predetermined microstructure. The at least one determined characteristic and other characteristics of the at least one pulse are sufficient to locally process the predetermined microstructure without causing the undesirable changes.

Abstract: A method, system and computer program product for assembling an optical module incorporates a far field pattern (FFP) optical measurement system and optionally a near field pattern (NFP) optical measurement system to obtain information about the axis and/or the divergent angle of light output from the optical elements to be assembled as part of the optical module. The optical elements include a light-emitting element, such as a laser diode, and at least one optical component, such as a collimating lens or a focusing lens. The system for assembling the optical module further includes a stage having the light-emitting element mounted thereon, a holding mechanism configured to hold and position the optical components to desired positions based on the measurements from the FFP and/or NFP optical measurement systems. A controller can control the stage, the holding mechanism and a fixing device configured to fix the positions of the optical elements once the optical elements are positioned in the desired positions.

Abstract: A method of determining at least one parameter that is characteristic of the angular distribution of light illuminating an object in a projection exposure apparatus is described. This parameter may be, for example, a pupil asymmetry. The method comprises the step of inserting a filter element in or in close proximity of a pupil plane of an illumination system that is arranged between a light source and the object. The filter element has a filter function that varies in an azimuthal direction with respect to the optical axis of the illumination system. Then the intensity of the light in a plane downstream of the pupil plane is measured. After rotating the filter element around the optical axis by an angle ?, the measurement of the intensity is repeated. From the filter function, the angle ? and the measured intensities the parameter is measured.

Abstract: An area CCD scanner (image reader) comprises an LED unit (light source), an area CCD and an image-forming lens. The LED unit includes a large number of light emitting elements of each color of blue, green, red and infrared. Light emitted from the LED unit and having passed through a photographic film is received by the area CCD and is converted into an electric signal, which is outputted as photographic image data. When the light source is inspected, a focal point of the image-forming lens is adjusted to a light emitting surface of the LED unit. Then, the LED unit is turned on without setting the photographic film to receive the light thereof with the area CCD. On the basis of the obtained electric signal, a light-emission state of the LED unit is shown on a display.

Abstract: This invention provides a radiation directing device, including a screen having a mirrored surface interrupted by one or more pin holes that pass through the screen, the pin holes having an elliptical shape. The invention further provides an apparatus, including (a) a screen having a mirrored surface interrupted by one or more pin holes passing through the screen; and (b) a detector for detecting radiation reflected by the mirrored surface, wherein the detector determines a position of a radiation beam relative to the pin hole.

Abstract: In an optical characteristic measuring method for measuring an optical characteristic of a projection optical system (10a), a reticle (9) having a plurality of patterns (TP) is supplied, and scattered light from an aperture is directed to the plurality of patterns (TP), whereby light beams are projected onto the plurality of patterns in mutually different directions, by which images of the plurality of patterns are formed through the projection optical system (10a). Positions of images of the plurality of patterns, respectively, are detected and, by use of the result of detection, the optical characteristic of the projection optical system is detected. This accomplishes an optical characteristic measuring method and a reticle to be used therefor, which are suitable for measuring an optical characteristic of an optical system such as wavefront aberration, for example, at high precision.

Abstract: An optical sampling waveform measuring apparatus can measure waveform of a high-speed signal light P8 sensitively, accurately, and in high time resolution, Raman shift light which is generated from a light pulse having a narrower pulse width than the signal light to be measured is used as a sampling light pulse.

Abstract: Before measuring a wavefront aberration of a projection optical system, an image formation position of an image of a pattern of a test reticle which is formed on a predetermined surface is detected by an AF sensor. Based on a result of this detection, the position of an incident surface of a wavefront aberration measurement unit is adjusted, and a position of an image of the pattern with respect to the incident surface is adjusted. After this adjustment, the image of the pattern formed through the projection optical system is detected by the wavefront aberration measurement unit, and a wavefront aberration detection section is used to obtain wavefront aberration information of the projection optical system based on a result of this detection.

Abstract: There is disclosed a measuring method of illuminance unevenness of an exposure apparatus in which the illuminance unevenness resulting from a projection optical system, to project the light passed through the photomask onto the finite area on the photosensitive substrate via the projection optical system and to expose the photomask to the light, the method comprising calculating an average value of transmittance of the projection optical system of each path of the light emitted from one point of the photomask and reaching an imaging point for each of a plurality of imaging points in the finite area on the photosensitive substrate, and calculating the illuminance unevenness in the finite area on the photosensitive substrate from the average value of the transmittance obtained for each imaging point.

Abstract: In evaluating whiteness of light from a light source or a luminaire, whiteness W is given by the following equation, W=?5.3C+100, wherein chroma C is determined by the CIE 1997 Interim Color Appearance Model (Simple Version).

Abstract: A piezoelectric sensor (7) is dedicated to making a precise measurement of the light amplitude of pulses (2) from a laser (1), so that quantitative measurements such as photo-acoustic spectroscopy can be used to precisely measure the concentration of some bodies in a solution.

Abstract: A test system for positioning and measuring the far-field pattern of a laser diode under test (LDUT) using a single objective lens and two relay lenses. Positioning is achieved by passing light from the LDUT through a video microscope formed by the objective lens and a first relay lens, which focuses the light onto an image plane for capture by a first camera. Far-field pattern measurement is performed by reflecting a portion of the focused light through a second relay lens, which collimates the light and directs the unfocused light onto an infinity image plane, where it is captured by a second video camera. Angular orientation is achieved using a laser collimator that reflects beam energy from a datum plane of the LDUT. The reflected beam energy forms a point image at the infinity image plane that is used to determine and/or adjust the angular orientation of the LDUT.

Abstract: An optical beam profiler using a spatial light modulator and photodetector. In an embodiment, the spatial light modulator is a two-dimensional (2-D) small tilt digital micromirror device. The profiler features fast speed, digital controls, low polarization sensitivity, and high measurement repeatability. The 2-D multi-pixel device-based profiler allows the use of several beam profile measurement concepts including moving knife edge, scanning slit, moving pinhole, variable aperture, and 2-D photodiode array. The proposed digital optical beam profiler can be implemented with any type of digitally operated 2-D spatial light modulator device such as using liquid crystals, magneto-optics, multiple quantum wells, electro-optic polymers, and photonic crystals.

Abstract: The system includes a first polarizing element; an electro-optically driven birefringent element; a second polarizing element; an optical assembly; and, an optical-to-electronic imaging sensor assembly. The first polarizing element receives an incoming optical wavefront and provides a linearly polarized output therefrom. The electro-optically driven birefringent element receives the linearly polarized output and produces two polarization eigenwaves, an output of the birefringent element being elliptically polarized. The second polarizing element has a polarization axis perpendicular to a polarization axis of the first polarizing element. The second polarizing element receives the output from the birefringent element and provides a linearly polarized output. The optical assembly receives the output of the second polarizing element and forms a real image therefrom.

Abstract: A method of quantitative determination of the phase of a radiation wave field including the steps of producing a representative measure of the rate of change of intensity of the radiation wave field over a selected surface extending generally across the wave field; producing a representative measure of intensity of the radiation wave filed over the selected surface; transforming the measure of rate of change of intensity to produce a first integral transform representation and applying to the first integral transform representation a first filter corresponding to the inversion of a first differential operator reflected in the measure of rate of change of intensity to produce a first modified integral transform representation; applying an inverse of the first integral transform to the first modified integral transform representation to produce an untransformed representation; applying a correction based on the measure of intensity over the selected surface to the untransformed representation; transforming the

Abstract: A propagation measuring apparatus for measuring propagation characteristics of an object to be measured includes a first light source for outputting a first optical signal of a first frequency, a second light source for outputting a second optical signal of a second frequency, a terahertz light outputting unit for generating terahertz light of a frequency, which is equal to a difference between the first and second frequencies, by using the first and second optical signals and radiating the terahertz light to the object to be measured, a first detecting unit for detecting the terahertz light passing through the object to be measured and a measuring unit for measuring the propagation characteristics of the object to be measured based on the terahertz light detected by the first detecting unit.

Abstract: A device for determining the intensity and phase of a coherent light beam (F) in a cross-section of the beam comprises a calculator (1), a camera (2), a detector plane (3), an optical sampling element (4), and two mirrors (5, 6). The device measures the intensity Ii (i=1, . . . N) of the beam in N planes (N?3). The camera (2) is equipped with a single detector plane (3). The optical sampling element (4) and the two mirrors (5, 6) assemble N distinct elementary beams, generated based on the coherent light beam (F), on N distinct zones of the single detector plane (3).

Abstract: A device for detecting the direction of a light source. The device has a pin-hole lens that allows a collimated light beam to excite a light sensing surface behind the lens. The output from the light sensing surface is passed to a processor that determines the position of the surface that has been excited and the direction of the light source. When the position of one or more light sources is known, the device may further determine its own position. The devices may be used in a location system to provide known reference points to a network of other devices. The light sources may be modulated, in which the device can select or identify a particular light source based upon its modulation pattern.

Abstract: A method for adjusting an optical system of an energy beam apparatus by using a mark signal that is obtained by one-dimensionally or two-dimensionally scanning a mark on a sample with an energy beam. The mark has a one-dimensional or two-dimensional periodic structure. A first mark signal is detected by scanning the mark with a beam. The mark is set on the optical axis of the optical system. A second mark signal is detected by scanning the mark with a beam. The mark is located at a position that is deviated from the optical axis. A deviation of a deflection position is determined based on a phase difference between the first and second mark signals.

Abstract: A method of determining at least one parameter that is characteristic of the angular distribution of light illuminating an object in a projection exposure apparatus is described. This parameter may be, for example, a pupil asymmetry. The method comprises the step of inserting a filter element in or in close proximity of a pupil plane of an illumination system that is arranged between a light source and the object. The filter element has a filter function that varies in an azimuthal direction with respect to the optical axis of the illumination system. Then the intensity of the light in a plane downstream of the pupil plane is measured. After rotating the filter element around the optical axis by an angle &PHgr;, the measurement of the intensity is repeated. From the filter function, the angle &PHgr; and the measured intensities the parameter is measured.

Abstract: A projection exposure apparatus for imaging and printing a pattern, formed on a first object, upon a second object through a projection optical system. The projection exposure apparatus includes a storing device for storing information related to light intensity distribution on a pupil plane of the projection optical system in a reference state, and a detecting device for detecting a wavefront of the projection optical system in an arbitrary state, on the basis of the stored information.

Abstract: A wavefront sensor for measuring a wavefront contains an array of lenslets, a detector array, and a mask having a temporally fixed pattern containing one or more opaque regions that are substantially opaque to light from the wavefront. The mask comprises one or more transmissive regions that are transmissive of light from the wavefront. The mask and the array of lenslets are disposed such that light from the wavefront that is transmitted by the transmissive regions is focused by onto the detector array by the array of lenslets. The mask is adapted to be selectably disposed to any one of a plurality of predetermined positions, wherein a different group of lenslets from the array focuses light from the wavefront onto the detector array depending on which of the plurality of predetermined positions is selected.

Abstract: The invention concerns a device for analysing a wavefront with enhanced resolution. The inventive wavefront analysing device, of the Hartmann or Shack-Hartmann type, comprises in particular a set of sampling elements arranged in an analysis plane, and forming as many micro-lenses for sampling the incident wavefront, and a diffraction plane wherein are analysed the Airy discs of the different micro-lenses illuminated by the incident wavefront. The invention is characterised in that the shape of each micro-lens is such that the associated diffraction figure has in the diffraction plane one or several preferential axe(s), and the micro-lenses are oriented in the analysis plane such that the preferential axe(s) of the diffraction figure of a micro-lens are offset relative to the preferential axes of the diffraction figures of neighbouring micro-lenses, thereby enabling to limit the overlapping of the diffraction figures.

Abstract: Methods of measuring widths of illumination spots and distances between two points, and predicting detected signal widths are provided. Systems, software, and kits for performing the methods of the invention are also provided.

Abstract: A method for adjusting an optical system of an energy beam apparatus by using a mark signal that is obtained by one-dimensionally or two-dimensionally scanning a mark on a sample with an energy beam. The mark has a one-dimensional or two-dimensional periodic structure. A first mark signal is detected by scanning the mark with a beam. The mark is set on the optical axis of the optical system. A second mark signal is detected by scanning the mark with a beam. The mark is located at a position that is deviated from the optical axis. A deviation of a deflection position is determined based on a phase difference between the first and second mark signals.

Abstract: A method and apparatus for rapid measurements of far-field radiation profiles having a large dynamic range from an optical source is disclosed. Some embodiments of the apparatus include a collector coupled to a rotating hub so that the rotation of an entrance to the collector defines a plane, a detector coupled to receive light captured at the entrance to the collector, and detector electronics having a programmable gain coupled to receive a signal from the detector, Some embodiments may include a rotatable entrance mirror for reflecting light from the optical source into the plane of the entrance of the collector. In some embodiments, the optical source is fixed relative to the plane of the entrance of the collector. In some embodiments, the optical source is rotatable in the plane defined by the entrance of the collector. In some embodiments, the source can be an optical fiber. In some embodiments, the source can be a material irradiated by a laser.

Abstract: A technique for measuring the modal power distribution of an optical source (for example, a laser) launching pulses into a multimode fiber involves a characterization of the multimode fiber itself in terms of its differential modal delay. A reverse differential mode delay measurement is then performed to characterize the interaction of the optical source with the multimode fiber. By knowing these characteristics, the modal power distribution of the source into the fiber can then be determined by using a reconstruction algorithm.

Abstract: A two-dimensional array of lateral-effect detectors (or position-sensing devices) is used to simultaneously measure multi-point centroidal locations at high speed. It is one of the primary components of a high-speed optical wavefront sensor design comprising a Shack-Hartmann-type lenslet array and associated analog circuitry including analog-to-digital (A/D) converters, and digital micro-processors. The detector array measures the centroidal location of each incident beam emerging from the lenslet array and calculates the local wavefront slope based on the beam deviations from their respective subaperture centers. The wavefront sensor is designed for high temporal bandwidth operation and is ideally suited for applications such as laser-beam propagation through boundary-layer turbulence, atmospheric turbulence, or imperfect optics. The wavefront sensor may be coupled with a deformable mirror as primary components of an adaptive optics system.

Abstract: A method for adjusting an optical system of an energy beam apparatus by using a mark signal that is obtained by one-dimensionally or two-dimensionally scanning a mark on a sample with an energy beam. The mark has a one-dimensional or two-dimensional periodic structure. A first mark signal is detected by scanning the mark with a beam. The mark is set on the optical axis of the optical system. A second mark signal is detected by scanning the mark with a beam. The mark is located at a position that is deviated from the optical axis. A deviation of a deflection position is determined based on a phase difference between the first and second mark signals.

Abstract: A light intensity distribution measuring method for measuring the light intensity distribution of a laser beam emitted by a semiconductor laser comprises the steps of measuring light intensities at a plurality of locations in a laser beam emitted by a semiconductor laser and applying their measurement results to a t distribution function to calculate the light intensity distribution. A light intensity distribution measuring device is also described.

Abstract: The optical system of the present invention includes a lens system assembly, a spectral filter material and a pixel array configured such that small, distant, light sources can be reliably detected. The optical system of the present invention provides accurate measurement of the brightness of the detected light sources and identification of the peak wavelength and dominant wavelength of the detected light sources. Use of the optical system of the present invention provides the ability to distinguish headlights of oncoming vehicles and taillights of leading vehicles from one another, as well as, from other light sources.

Abstract: The present invention provides a continuous-zoom imaging device of an interferometer. Reflected lights of a reference plane and a test plane interfere with each other to generate an interference pattern. A collimation device converts a parallel light of the interference pattern into a convergent light. An optical path adjustment means guides the light to a polarizing beam splitter. A continuous-zoom device adjusts the magnification ratio of the interference pattern on the imaging passageway and to output an object image, which is then imaged on a charge-coupled device. The present invention can improve the quality of the interference pattern without using any rotating diffuser, and thus has the characteristics of reduced number of components, lowered cost, and shrunk volume. Besides, the present invention can utilize a joint device to connect the continuous-zoom device and an attenuator so as to achieve automatic light adjustment and convenient operation.

Abstract: A projection optical system for forming an image of a pattern in a first plane onto a second plane using exposure light in a wavelength region of shorter than 200 nm. When a projection pattern placed in the first plane and having a dark pattern and a light pattern around the dark pattern is projected onto the second plane, an average illuminance in a area where a projected image of the dark pattern is formed in the second plane is 8 or less, where an illuminance of an image of the light pattern around the dark pattern in the second plane is set to be 100.

Abstract: A system is disclosed for analyzing an illumination field of a line of laser illumination. The system includes a first movable unit, a second movable unit, and a sensor unit. The first movable unit includes a first opening through which at least a portion of the illumination field may pass. The first movable unit is adapted for movement in a first direction. The sensor unit is adapted to receive illumination and to produce a sensor output signal representative a characteristic of the illumination field. The second movable unit includes a second opening through which at least a portion of the illumination field may pass. The second movable unit is positioned between the first movable unit and the sensor unit and is adapted for movement between at least a first position in which very little or no light from the illumination field may reach the sensor unit, and a second position in which a relatively high amount of light from the illumination field may reach the sensor unit.

Abstract: A system and method of wavefront sensing with a Shack-Hartmann wavefront sensor precisely locates focal spots on a detector array, and determines the location of the lenslet array with respect to the detector array.

Abstract: An agile optical beam profiler using a two-dimensional small tilt digital micromirror device/chip, a translation stage, and single photodetector or pair of photodetectors. A method of profiling an optical beam includes positioning a programmable spatial light modulator in an incident optical beam and sequentially moving the spatial light modulator to at least one position in a first planar direction in a displacement increment less than a pixel width of the spatial light modulator. The method also includes directing respective portions of the optical beam to a photodetector at each position of the spatial light modulator. The method may also include calibrating the photodetectors by directing a portion of the beam to the photodetector, then directing the entire beam, or a remaining portion of the beam, to the photodetector, and normalizing the detected power of the portion with the detected power of the entire beam, or remaining portion, respectively.

Abstract: A device for the analysis of an optical wavefront includes an array (ML) of microlenses (Li), and signal processing elements. Each mircolens (Li) defines a subaperature (Spi), and focuses an elementary surface of the wavefront, intercepted by the subaperature, for forming a spot (Ti) on the detector. For each subaperature (Spi), a zone (Zi) of assumed localization of the spot is defined. The processing unit makes it possible to establish a measurement file associating to each subaperature the position of this spot. The structure of the array (ML) presents one or several local variations. By comparing the contribution of these local variations taken from the measurement file, with their contribution taken from a reference file, the displacement between the subaperature from which a detected spot is derived and the subaperature that defines the zone of assumed localization wherein the spot is located is measured.

Abstract: A process of measuring the radiant intensity profile of an effective source of a projection image system that has an effective source, an object plane, an imaging objective, an exit pupil, and an image plane. The improved process consists of selecting at least one field point and a corresponding aperture plane aperture and projecting a plurality of images of the selected field point through the corresponding selected aperture plane aperture at a plurality of various intensities of the effective source. By analyzing the recorded images of the effective source at various intensities it is possible to determine a radiant intensity profile of the image source at the selected field point.

Abstract: The invention relates to a device for determining the intensity and phase of a coherent light beam (F) in a cross-section of the beam.

Abstract: A test system for positioning and measuring the far-field pattern of a laser diode under test (LDUT) using a single objective lens and two relay lenses. Positioning is achieved by passing light from the LDUT through a video microscope formed by the objective lens and a first relay lens, which focuses the light onto an image plane for capture by a first camera. Far-field pattern measurement is performed by reflecting a portion of the focused light through a second relay lens, which collimates the light and directs the unfocused light onto an infinity image plane, where it is captured by a second video camera. Angular orientation is achieved using a laser collimator that reflects beam energy from a datum plane of the LDUT. The reflected beam energy forms a point image at the infinity image plane that is used to determine and/or adjust the angular orientation of the LDUT.

Abstract: An apparatus and method for wavefront sensing that includes: employing two moiré gratings in an optical path; optically Fourier transforming a moiré deflectogram produced by the gratings; variably transmitting the transformed moiré deflectogram; and receiving an image of the variably transmitted and transformed moiré deflectogram. The variable transmission is best accomplished by transmission filter, a transmissive optic encoding intensity information upon the moiré deflectogram as a function of fringe angle. For example, the function can be a triangular transmission function centered on the (0,0) order spatial frequency spot and oriented at 45 degrees to the y-axis. The optical Fourier transform is accomplished by a lens and the variable transmission by an apodized slit.

Abstract: A light monitoring system provides a sensing unit coupled to a luminaire. The sensing unit monitors both the input and the output of the luminaire for both current and voltage. In this manner, a variety of problems with the luminaire can be detected by the sensor and this information can be passed to monitoring equipment that is either hard-wired or remotely coupled to the sensing unit.

Abstract: An arrangement for determining the position of a light source includes a light-sensitive detector device and an arrangement for casting a shadow onto part of the light of the light source shining onto the detector device. The shadowing arrangement is formed by at least one rotationally symmetrical body.

Abstract: There is disclosed a dose monitor method comprising illuminating a mask with illumination light, which is disposed in a projection exposure apparatus and in which a dose monitor pattern is formed, passing only a 0th-order diffracted light through a pupil surface of the projection exposure apparatus in diffracted lights of the dose monitor pattern, and transferring a 0th-order diffracted light image of the dose monitor pattern onto a substrate to measure dose, wherein during the illuminating, a center of gravity of the 0th-order diffracted light image passed through the dose monitor pattern on the pupil surface of the projection exposure apparatus is shifted from an optical axis of the projection exposure apparatus.

Abstract: There is described a method of characterizing a short laser pulse, the method comprising the steps of obtaining root-mean-square widths of the pulse through second order moments of the pulse; obtaining a spectral width of the pulse using the root-mean-square widths; obtaining a root-mean square temporal width of the pulse; and defining a Pulse Quality Factor proportional to a product of the spectral width and the temporal width. This approach does not require complete characterization of laser pulses and eliminates the need of any assumption to interpret autocorrelation traces. The method can be applied to pulses of arbitrary shape.

Abstract: A method and apparatus for measuring a wave front aberration of a projection lens with high precision and a related calibration method. The apparatus includes: either a light source and an element producing a first point source in combination with the light source or a first point source generating part; a magnifying projection optical system projecting and magnifying a point image of the first point source projected by a test object; a detector detecting the magnified point image projected and magnified by the magnifying projection optical system; a supporting member supporting the magnifying projection optical system and the detector; a calculating part calculating a wave front aberration; and either a second point source producing element or a second point source generating part.

Abstract: An illuminance measurement apparatus for measuring the illuminance of illumination light on an image plane of a projection optical system of an exposure apparatus designed to project the image of a pattern from an illuminated mask on a substrate held on a substrate stage by the projection optical system, including an illuminance meter detachably attached to the substrate stage, the illuminance meter having an illuminance detector, a transmitter for wirelessly transmitting a measurement result of the illuminance detector, a storage cell, and a photoelectric converter for converting part of the illumination light photoelectrically and storing it in the storage cell, and a receiver for receiving the wireless signal including the measurement results transmitted by the transmitter.

Abstract: The objective of the present invention is providing a method and a simple instrument that can be used on a routine basis to accurately and quickly measure the focus position, waist radius, divergence, quality, power and power density of a laser beam. The measurement is performed by scanning a thin film of a nonlinear optical material in the focal region along the propagation direction of the beam and registering the variation of the on-axis intensity of the laser beam by a photodetector.

Abstract: An adaptive optics system configured as an optical phase front measurement system which provides for relatively high resolution sampling as in holographic techniques but without the need for a reference beam. The optical phase front measurement system includes one or more lenses and a spatial light modulator positioned at the focal plane of the lenses and a camera which enables the phase front to be determined from intensity snapshots. The phase front measurement system allows for relatively long range applications with relatively relaxed criteria for the coherence length of the laser beam and the Doppler shift. As such, the system is suitable for a wide variety of applications including astronomy, long range imaging, imaging through a turbulent medium, space communications, distant target illumination and laser pointing stabilization.

Abstract: An illumination apparatus is provided for a hand-held imager preferably to provide diffuse illumination for encoded symbology carried directly upon an article (component, etc) or upon a substrate carried by an article. The illumination apparatus is disposed proximate the front of the hand-held imager and is configured to permit light reflected from the target to pass through the illumination apparatus and onto a CCD image receiver. An array of unlensed LED's is disposed to cast approximately or substantially lambertian illumination in a direction away from the target to be imaged and into the hand-held housing to impinge upon surfaces of an illuminator to receive the illumination and, in turn, project efficient and diffuse dark field illumination through the array of unlensed LED's and towards and onto a location where a target to be imaged would be disposed.