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We have introduced an athermal chart that plots chromatic dispersive power and thermal dispersive power on a Cartesian coordinate, and we give the design method of a multilens system in contact that satisfies achromatism and athermalization. The advantages of this chart are (1) that the condition of achromatism and athermalization is clear and (2) that the approximate power of the lenses that compose the multilens system is easily found on the chart. Design indices are given through a few design examples with an athermal chart.

We propose a configuration of an off-axis three-mirror system for maximum compactness and brightness. The chief ray is arranged to cross three times inside the system, and the system has a round configuration for compactness. We introduced into the design a ray triangle formed by the reflection points of the chief rays at the mirrors. The ray triangle indicates the size and the brightness of the system. Based on the proposed configuration, a design example of a 4 degrees x 4 degrees field of view is shown. The F-number of the system is 2.2, in close agreement with the estimation from the ray triangle.

We introduce a projective athermal chart that is produced as a view plane of the perspective projection of a three-dimensional space consisting of two chromatic dispersive powers and the mean thermal dispersive power. In addition, we show a design method for dual-band optical systems with this chart and a design example of a three-lens optical system operating in the 3-5- and 8-12-mum wavelength bands.

This paper introduces the recent development of 3D imaging LADAR (LAser Detection And Ranging) in Mitsubishi Electric Corporation. The system consists of in-house-made key devices which are linear array: the laser, the detector and the ROIC (Read-Out Integrated Circuit). The laser transmitter is the high power and compact planar waveguide array laser at the wavelength of 1.5 micron. The detector array consists of the low excess noise Avalanche Photo Diode (APD) using the InAlAs multiplication layer. The analog ROIC array, which is fabricated in the SiGeBiCMOS process, includes the Trans-Impedance Amplifiers (TIA), the peak intensity detectors, the Time-Of-Flight (TOF) detectors, and the multiplexers for read-out. This device has the feature in its detection ability for the small signal by optimizing the peak intensity detection circuit. By combining these devices with the one dimensional fast scanner, the real-time 3D range image can be obtained. After the explanations about the key devices, some 3D imaging results are demonstrated using the single element key devices. The imaging using the developed array devices is planned in the near future.