Laser Doppler vibrometer

About: Laser Doppler vibrometer is a research topic. Over the lifetime, 6319 publications have been published within this topic receiving 76068 citations.

Direct detection doppler lidar method and direction detection doppler lidar device

Abstract: The invention relates to a method for the direct detection Doppler lidar measurement of speeds, a laser beam (15) being directed onto the medium (16) to be measured and the radiation (18) reflected by the medium (16) being measured by means of a detector (35). In order to optimize the dynamic scope of a direct detection Doppler lidar device (10), the method comprises the following steps: a) emitting a plurality of laser pulses per measurement (52) and b) integrating a plurality of laser pulses (51, 81 a, 81 b, 81 c) received by the detector (35) per measurement (52). The invention further relates to a direct detection Doppler lidar device (10) which is suitable for carrying out said method.

Laser light source device and image display apparatus

Abstract: A laser light source device has a laser light source for emitting a laser beam, a laser driver for driving the laser light source, a light-collecting lens for collecting the laser beam and reflecting a part of the laser beam, an optical sensor for receiving a reflected laser beam which has been reflected by the light-collecting lens and outputting a detection signal corresponding to intensity of the reflected laser beam, and a controller for controlling driving of the laser light source by the laser driver in accordance with the detection signal, and the light-collecting lens is disposed in a eccentric-rotated state so that an optical axis of the light-collecting lens has a tilt with respect to a central ray of the laser beam being incident on the light-collecting lens.

High speed fiberoptic laser module

Abstract: A small module contains means for converting an electrical signal to a correspondingly modulated light signal on an optical fiber. Frequency of the signal can range from D.C up to many gigahertz. A semiconductor laser diode is mounted on a high thermal conductivity substrate on a thermoelectric cooler for controlling laser temperature. The optical fiber output is soldered to the laser substrate with an end in alignment with the laser junction. A laser bias circuit is on a connection substrate adjacent to the laser substrate. A connection substrate also includes a deposited signal lead line connected to the bias circuit by an impedance matching means. Electrical signals from the pin of an external coaxial connector are coupled to the lead line. The laser bias circuit and signal lead line are electrically connected to the laser diode by wires between the connection substrate and the laser substrate. A photodiode in the module in the light path from the laser provides a control signal.

Optical fiber accelerometer based on a silicon micromachined cantilever.

Abstract: An intensity-modulated fiber-optic accelerometer based on backreflection effects has been manufactured and tested. It uses a multimode fiber placed at a spherical mirror center, and the beam intensity is modulated by a micromachined silicon cantilever. This device has applications as an accelerometer and vibrometer for rotating machines. It exhibits an amplitude linearity of ±1.2% in the range of 0.1–22 m s−2, a frequency linearity of ±1% in the range of 0–100 Hz, and a temperature sensitivity of less than 0.03%/°C. The sensor is devoted to a wavelength-division multiplexing network.