Compact and high-precision range finder with wide dynamic range and its application

A real mass application for VCSELs is their use in optical mice and sensing. As illumination source for sensing applications VCSELs offer a better performance than LEDs. The even more advanced approach of laser self-mixing interference sensors allows a next step in integration, accuracy and new application fields. This chapter summarizes the major requirements towards VCSELs in illumination for sensing applications and gives typical specifications. A detailed description of the production process and the achieved reproducibility makes clear that these VCSELs are ideally suited for production in large quantities. In the second half of the chapter the self-mixing interference method is described in more detail and a highly integrated two axes laser Doppler interferometer is shown. This product is designed for a laser mouse but offers a number of other sensing applications.

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“…This includes diverse topics like velocity measurement in automotive applications [14], flow measurements [15] or range finders [16].…”

Section: More Smi Applicationsmentioning

confidence: 99%

VCSELs for Optical Mice and Sensing

Grabherr

Moench

Pruijmboom

2012

Springer Series in Optical Sciences

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“…One method of distance measurement is time of flight while reflectance obtain from the amplitude of reflected pules. PLR using the time of flight method to measure distance is frequently used in level control, system vision, 2D and 3D object scanning, medical engineering and many other applications [3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Neural Method for Two Dimensional (2D) High Contrast Imaging in Pulsed Laser Radar

Joodaki

Kompa

Arshad

et al. 2001

31st European Microwave Conference, 2001

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In this paper we have developed a new imaging method which can obtain the grey levels directly from the output waveform of Pulsed Laser Radar (PLR). A simple digital signal processing technique and multi layer perceptrons (MLP) type neural network (NN) have been used to obtain the grey level information from the pulse shapes. The method has been implemented in a real PLR to improve contrast and speed of 2D imaging in PLR. For comparison with the standard method, a picture consisting of 16 grey levels (from 0 for black to 1 for white) using both methods. Because of the ability of NNs in extracting the information from nonlinear and noisy data and pre-processing of the noisy input pulse shapes to the NN, the average and maximum errors in the grey levels in comparison with standard method more than 88.5% and 72.6% improved, respectively. Because in this method the effect of the noise is decreased, it is possible to make to image at the same resolution as in standard method with lower averaging in the sampling unit and this dramatically increases speed of the measurements.

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“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Current noncontact position/object sensor technologies include: ͑i͒ fine position inductive types that operate at short ranges, such as eddy current, magnetoresistive, and Hall effect sensors; ͑ii͒ optical time of flight and optical coherence position sensors such as laser interferometery, optical triangulation, and optical fiber methods; [12][13][14] and ͑iii͒ acoustic or ultrasonic sensors. Current noncontact acoustic or ultrasonic position/object detections are based on time-of-flight or time-delay estimation using ͑i͒ pulse mode [2][3][4][5][6][7]9,11 and ͑ii͒ continuous wave ͑cw͒ mode.…”

Section: Introductionmentioning

confidence: 99%

An acoustic position sensor

Dong

Bai

et al. 2003

Review of Scientific Instruments

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This article presents an acoustic method-the resonance acoustic field sensor or piezoelectric-sound-resonance cavity ͑PSRC͒-for object position detection. This method utilizes the change of acoustic radiation impedance as a sensing mechanism. The PSRC both generates and detects a resonance acoustic field, along both the axial and transverse directions. We have discovered that an inserted object or an object motion in the sound radiation field results in changes in both the voltage and phase of the PSRC. Results have shown that a minimum object displacement of Ͻ10 m can be detected in the axial direction ͑and Ͻ100 m in the transverse͒ by this method.

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Compact and high-precision range finder with wide dynamic range and its application

Cited by 86 publications

References 3 publications

VCSELs for Optical Mice and Sensing

VCSELs for Optical Mice and Sensing

Neural Method for Two Dimensional (2D) High Contrast Imaging in Pulsed Laser Radar

An acoustic position sensor

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