We have proposed a novel mobile healthcare platform, combining a pocket-sized colorimetric reader (13.5 × 6.5 × 2.5 cm(3)) and commercially available 10-parameter urinalysis paper strips (glucose, protein, glucose, bilirubin, urobilinogen, ketones, nitrite, pH, specific gravity, erythrocytes, and leukocytes), capable of sending data with a smart phone. The reader includes a novel colorimetric multi-detection module, which consists of three-chromatic light-emitting diodes, silicon photodiodes and a novel poly(methylmethacrylate) (PMMA) optical splitter. We employed data reading methods using conversions of the signal data (red, blue, and green) to the hue (H) color map or the Y model data, and used a curve-fitting method for the quantification. The reader is battery-powered, inexpensive, light-weight, and very speedy in analysis. And, it was applied to detection of a thousand of human urine samples and demonstrated reliable quantification of urinary glucose and protein. The features can be used by unskilled people on-site to transfer the analyzed data to experts off-site.

We propose a method capable of focusing a laser beam on a substrate automatically via fluorescence detection from the resin of a two-photon nanofabrication system. When two-photon absorption (TPA) occurs by focusing the laser beam in the resin, fluorescence is emitted from the focusing region in the visible range. The total pixel number above the threshold value of the fluorescence images obtained by a CCD camera is plotted on a graph in accordance with the focus position. By searching for the position when the total pixel number undergoes an abrupt change in the pre-TPA region, the correct configuration of the focused laser beam can be found. Through focusing tests conducted at four vertices of a 500 μm x 500 μm square placed arbitrarily inside SCR500 resin, the errors of the autofocusing method were found to range from -100 nm to + 200 nm. Moreover, this method does not leave any polymerized marks. To verify the usefulness of the autofocusing method, the fabrication of a pyramid structure consisting of 20 layers was attempted on a coverglass. It was completely fabricated without losing a layer.

No abstract

for various applications. The system measures the range of scenes of interest and generates three-dimensional data. With such data, LADAR systems can be used for topographic mapping, automatic target recognition, autonomous safe landing and so on [1][2][3]. To complete these kinds of missions, range precision is the most important parameter of LADAR systems.Various techniques are employed to obtain optical distance measurements including interferometry, time of flight (TOF) and triangulation [4]. For long-range measurements and working outdoors, TOF methods are employed in many LADAR systems [5]. The conventional TOF LADAR system transmits a laser pulse (start signal), triggering the time to digital converter (TDC). The transmitted laser pulse reflects off a target. The laser-return pulse (stop signal) is detected by an avalanche photodiode (APD). The APD generates an electrical signal to stop the TDC. The time interval between the start signal and the stop signal is converted into distance. Range precision is determined by the closeness of such measurements to independent range results acquired under identical environmental circumstances [6].The range precision of the LADAR system depends on a number of factors including the laser pulse width, the timing resolution of the APD, the timing resolution of the TDC, shot noise and the timing jitters generated by electronics [7,8]. Because of these factors, range precision has a limit. Generally, the range precision of the conventional LADAR system is several centimeters [9, 10]. A commercial LADAR system has several millimeters in range precision [11]. To obtain better range precision, a shorter laser pulse width is needed. However, short laser pulses require a high-bandwidth APD and a high timing resolution TDC [12]. This limitation can be overcome by averaging with the improvement proportional to 1/√(the number of results averaged), as compared to a single measurement result Abstract We have proposed and demonstrated a novel technique to measure distance with high range precision. To meet the stringent requirements of a variety of applications, range precision is an important specification for laser radar systems. Range precision in conventional laser radar systems is limited by several factors, namely laser pulse width, the bandwidth of a detector, the timing resolution of the time to digital converter, shot noise and timing jitters generated by electronics. The proposed laser radar system adopts a Pockels cell and a quadrant photodiode and only measures the energy of a laser pulse to obtain range so that the effect of those factors is reduced in comparison to conventional systems. In the proposed system, the measured range precision was 5.7 mm with 100 laser pulses. The proposed method is expected to be an alternative method for laser radar system requiring high range precision in many applications.

In this paper, the improvement of range precision in a laser detection and ranging (LADAR) system by using two Geiger mode avalanche photodiodes (GmAPDs) is described. The LADAR system is implemented by using two GmAPDs with a beam splitter and applying comparative process to their ends. Then, the timing circuit receives the electrical signals only if each GmAPDs generates electrical signals simultaneously. Though this system decreases the energy of a laser-return pulse scattered from the target, it is effective in reducing the range precision. The experimental results showed that the average value of standard deviation of time of flights was improved from 61 mm to 37 mm when the pulse energy is 0.6 μJ. When the time bin width is 0.5 ns, the single-shot precision error of the LADAR system was also improved from 280 mm to 67 mm.