Abstract: An extended area “cavity type” blackbody for use as a radiometric reference for imaging systems may have a well in the form of a cube having four sidewalls and a back wall, and open at the front. The temperature of the back wall may be controlled independently of the temperature(s) of the sidewalls. This system may produce infrared radiance closer to an ideal radiator than typical extended area sources. A “simple” blackbody is disclosed, having a source plate with a front emitting surface; a ledge element disposed in front of and below the source plate for heating air in front of the source plate; and (optionally) another ledge element disposed in front of and above the source plate for cooling air in front of the source plate. A housing may support the source plate and ledge element, and a vent may be provided in front of and above the source plate. A resistive heater may be associated with the ledge element; and (optionally) TECs may be associated with the other (cooling) ledge element.

Abstract: Improved temperature independence in infrared light emitting diodes (IRLEDs). The active stage groups (ASGs) occur at or at an integer multiple of each antinode of the e-field of the desired center wavelength. The structure is designed to yield increased efficiency at low (cryogenic) temperatures with a wide range of operational temperature independence. The structure may be designed to provide a wide range of temperature independent operation near room temperature. The spacing (S) between the centers of the active stage groups may be varied to create a more broad and shallow peak of the temperature dependence of the antinode enhancement. The IRLED may be an interband cascade LED.

Abstract: In an infrared (IR) scene projector device or thermal emission array comprising a plurality of vertically aligned carbon nanotubes disposed proximate to a thermally conductive substrate, the plurality of carbon nanotubes (CNTs) may be (i) arranged as in FIGS. 2 and 4B as a sparsely populated forest, with large gaps between the CNTs; or (ii) arranged as in FIGS. 3 and 4C as patches (clusters) of CNTs separated by gaps; or (iii) arranged as a combination of clusters separated by gaps wherein each cluster comprises a sparsely populated forest of CNTs.

Abstract: An extended area “cavity type” blackbody for use as a radiometric reference for imaging systems may have a well in the form of a cube having four sidewalls and a back wall, and open at the front. The temperature of the back wall may be controlled independently of the temperature(s) of the sidewalls. This system may produce infrared radiance closer to an ideal radiator than typical extended area sources. A “simple” blackbody is disclosed, having a source plate with a front emitting surface; a ledge element disposed in front of and below the source plate for heating air in front of the source plate; and (optionally) another ledge element disposed in front of and above the source plate for cooling air in front of the source plate. A housing may support the source plate and ledge element, and a vent may be provided in front of and above the source plate. A resistive heater may be associated with the ledge element; and (optionally) TECs may be associated with the other (cooling) ledge element.

Abstract: A blackbody radiometric reference comprising a source plate or a target plate, metallic nanoparticles or other high emissivity coating disposed on the plate, and an intermediate coating such as paint. The plate may comprise copper, aluminum or composites thereof. Apparatus capable of functioning as a radiometric or thermometric reference. A pre-heater or weakly-coupled area may be disposed around or adjacent a highly thermally uniform area. A groove or perforations extending into a front surface of the source plate defining a weakly-coupled edge portion surrounding a thermally-controlled, optically-active area, and connected by bridges or structures thereto. An external probe may be located near the source plate for measuring ambient temperature, for compensating for ambient temperature or for radiative load on the blackbody.

Abstract: Drive circuit (100, 200, 300, 400) for LED thermal emitters in pixel elements of an infrared scene projector (IRSP). At least two current sources (Q1, Q2, Q5) provide output currents (I1, I2, I3) which may be summed and provided to a single LED (150), or provided independently to two or more LEDs (450A, 450B). The current sources may have different gains (G1, G2, G3), and different turn-on voltages (Voffset). This allows for different resolutions for different ranges of apparent temperatures, such as high resolution in a low range and low resolution in a high range, thereby facilitating a digital implementation of the drive circuit(s).

Abstract: Drive circuit (100, 200, 300, 400) for LED thermal emitters in pixel elements of an infrared scene projector (IRSP). At least two current sources (Q1, Q2, Q5) provide output currents (I1, I2, I3) which may be summed and provided to a single LED (150), or provided independently to two or more LEDs (450A, 450B). The current sources may have different gains (G1, G2, G3), and different turn-on voltages (Voffset). This allows for different resolutions for different ranges of apparent temperatures, such as high resolution in a low range and low resolution in a high range, thereby facilitating a digital implementation of the drive circuit(s).

Abstract: A blackbody radiometric reference comprising a source plate or a target plate, metallic nanoparticles or other high emissivity coating disposed on the plate, and an intermediate coating such as paint. The plate may comprise copper, aluminum or composites thereof. Apparatus capable of functioning as a radiometric or thermometric reference. A pre-heater or weakly-coupled area may be disposed around or adjacent a highly thermally uniform area. A groove or perforations extending into a front surface of the source plate defining a weakly-coupled edge portion surrounding a thermally-controlled, optically-active area, and connected by bridges or structures thereto. An external probe may be located near the source plate for measuring ambient temperature, for compensating for ambient temperature or for radiative load on the blackbody.