Laser is widely used in angle measurements. This paper presents several frequently used methods of angle measurement that utilize laser, including：autocollimation angle measurement, angle measurement based on internal-reflection effect, laser interference angle measurement, angle measurement with ring laser and angle measurement with CCD. The principle, actualities, application situation, superiority and defects of each method are discussed.
The work is devoted to the study of the formation features of high-quality closed modes based on total internal reflection effect in rectangular resonators of large (up to thousands wavelengths) size based on InGaAs/GaAs/AlGaAs laser heterostructures. Features of the spectral composition and spatial configurations of closed mode structures are experimentally investigated. The presence of frequency combs in the spectra was demonstrated and their correspondence to separate spatial configurations of closed modes was shown. The effect of a change in pumping and temperature on the mode composition is also considered.
The measurement of the rotational angle of the wheel is critical for the smart wheel force sensor (SWFS) to obtain the wheel forces defined in the vehicle coordinates. To simplify the structure of the SWFS and overcome the shortcomings of the traditional angular transducer, a new method to evaluate the rotational speed of the wheel and then calculate the rotational angle is proposed in this paper. In this method, the centripetal acceleration caused by the rotation is recorded by three accelerometers and used carefully. What’s more, the possible sources of error are classified and analyzed. Simulations and stand experiment are carried out to demonstrate the effectiveness of the proposed method.
Small-Angle Measurement of Laser Beam Steering Based on Total Internal-Reflection Effect