A reflective relay spectrometer design based on reflective optical relay systems, which is more compact in physical size and superior in spectral imaging quality than previous designs, is disclosed.

In one embodiment, an agricultural sampling apparatus is provided. The apparatus comprising: a wave emitter; a wave transmitter configured to direct the waves from the wave emitter as a plurality of linewise waves to irradiate surface points of the agricultural sample; a dispersive element configured to receive waves arriving from the sample and deflect the arriving waves in at least two directions depending upon the wavelength of an arriving wave; and a detector configured with a plurality of detection elements disposed in at least two dimensions, the detector configured to convert the waves arriving from the dispersive element to a signal.

An inspection apparatus is provided that comprises an optical target including a solid host material and a fluorescing material embedded in the solid host material. The solid host material has a predetermined phonon energy HOST.sub.PE. The fluorescing material exhibits a select ground energy level and a target excitation (TE) energy level separated from the ground energy level by a first energy gap corresponding to a fluorescence emission wavelength of interest. The fluorescing material has a next lower lying (NLL) energy level relative to the TE energy level. The NLL energy level is spaced a second energy gap FM.sub.EG2 below the TE energy level, wherein a ratio of the FM.sub.EG2/HOST.sub.PE is three or more.

Spectrometer designs are provided. The spectrometer includes two planar diffraction gratings disposed in a cascade, without intervening optics therebetween. Advantageously, the described configurations may promote both a high throughput and a high resolution, enabling the design of a portable device having sufficient resolution for on-site use or in the laboratory. In some implementations, two different secondary diffraction channels may be provided.

A spectral beam combining system includes a spectral channel splicer comprising a plurality of reflectors and a spectral beam combiner comprising a diffraction optical element such as a diffraction grating. This spectral beam combining system may facilitate combining an increased number of spectral channels thereby producing higher optical power of the combining beam system.

A particle imaging system may include a volume to contain a fluid having a suspended particle, electrodes proximate to the volume to apply an electric field to rotate the suspended particle, an optical sensor comprising a first region and a second region and a diffraction element to split an image of the suspended particle into a bright field image focused on the first region and a spectral image focused on the second region.

An optical filter may include a first reflector and a second reflector. The first reflector may include a plurality of first gratings having a first sub-wavelength dimension and being arranged to recur at a first interval in a first direction. The second reflector may be spaced apart from the first reflector and include a plurality of second gratings having a second sub-wavelength dimension and arranged to recur at a second interval in a direction parallel to the first direction. The first reflector and the second reflector may include different materials or different geometric structures from each other. Accordingly, it is easy to adjust the transmission wavelength characteristics of the optical filter.

The invention provides a combination of a sample container and energy dispersion device, and method of manufacture. Among possible applications is construction of compact spectrometers optimized for a single use. The sample container includes diffraction gratings such that, when the container is illuminated with collimated light and observed with optics focused at infinity, one obtains an optical spectrum useful for identifying and measuring the concentration of specimens placed in the container, applicable for chemical analysis and for screening fluids for chemical or biological analysis. The invention further provides methods to fabricate a combination of a sample container and energy dispersion device, wherein one such method utilizes an inflatable bladder and temperature-controlled templates to emboss gratings on both outside and inside faces of a given cuvette.

Spectrometer designs are provided. The spectrometer includes two planar diffraction gratings disposed in a cascade, without intervening optics therebetween. Advantageously, the described configurations may promote both a high throughput and a high resolution, enabling the design of a portable device having sufficient resolution for on-site use or in the laboratory. In some implementations, two different secondary diffraction channels may be provided.

An interlaced diffraction grating system and process are disclosed. The interlaced grating system includes an optical dispersive grating with alternating bands of unique grating densities wherein the number of unique grating densities is greater than or equal to two. The optical dispersive grating may be reflective or transmissive, and it may be fabricated by mechanical ruling, holography, or reactive ion etching of a binary mask. An interlaced grating allows additional utility for both point spectroscopic detection as well as hyperspectral imaging.