Phase-shifting laser diode interferometer using pulse modulation

Abstract

A phase-shifting laser diode interferometer that uses direct pulse modulation is proposed and demonstrated. We found that a laser beam with a wide range of wavelength variation at constant optical power could be generated when a pulsed current was injected into the laser diode. We constructed a highly accurate interferometer by using a pair of interferometers. Several experiments, such as observations of temporal interference signals and spatial interferograms, measurement of a concave mirror, and duplicate measurements, confirmed the characteristics of pulse modulation and demonstrated the effectiveness of our technique.

Installation for Physical Simulation of Laser Location Processes

“…Наявні в літературі дані по відбивним характеристикам об'єктів і фонів з урахуванням умов лазерної локації відносяться в основному до інтегральних амплітудних характеристик на довжинах хвиль видимого та ближнього інфрачервоного діапазону [2] і однопозиційних умов локації. Однак, навіть таких відомостей по амплітудним, а також часовим, просторовим і іншим відбивним характеристикам об'єктів і фонів для всього різноманіття параметрів систем і умов локації недостатньо [3,4].…”

Automated method for wavelength estimation in a two-beam interferometer based on the on–off switching of two laser-diode sources

“…The phase difference between the two arms of the interferometer depicted in figure 1 is expressed by f p l = nd 2 , 0 0 where l 0 is the nominal wavelength of the laser source. If the wavelength is changed from l 0 to l l + D 0 by the modulation of the input voltage (ΔV) of the source [9,10], the corresponding phase-step variation in equation (1) according to a jth wavelength modulation l D ( ) j can be approximated as:…”

Phase-shifting interferometer with pulse modulation based on a downsampling technique

“…Although we proposed a signal detecting technique in the previous paper, 8 we mention it briefly. However, it is difficult to control the wavelength with pulse modulation because the wavelength does not change linearly.…”