Ghost Beam Suppression in Deep Frequency Modulation Interferometry for Compact on-Axis Optical Heads

Mapping Intimacies ◽

10.20944/preprints202102.0305.v1 ◽

2021 ◽

Author(s):

Oliver Gerberding ◽

Katharina-Sophie Isleif

Keyword(s):

Frequency Modulation ◽

Unique Feature ◽

Estimation Algorithm ◽

Low Noise ◽

Wide Range ◽

Phase Estimation Algorithm ◽

Balanced Detection ◽

Beam Transmission ◽

Readout Scheme ◽

Monolithic Component

We present a compact optical head design for wide-range and low noise displacement sensing using deep frequency modulation interferometry. The on-axis beam topology is realised in a quasi-monolithic component and relies on cube beamsplitters and beam transmission through perpendicular surfaces to keep angular alignment constant when operating in air or vacuum, which leads to the generation of ghost beams that can limit the phase readout linearity. We investigate the coupling of these beams into the non-linear phase readout scheme of DFMI and demonstrate adjustments of the phase estimation algorithm to reduce this effect. This is done through a combination of balanced detection and the inherent orthogonality of beat signals with different relative time-delays in deep frequency modulation interferometry that is a unique feature not available for heterodyne, quadrature or homodyne interferometry.

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Ghost Beam Suppression in Deep Frequency Modulation Interferometry for Compact On-Axis Optical Heads

Sensors ◽

10.3390/s21051708 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1708

Author(s):

Oliver Gerberding ◽

Katharina-Sophie Isleif

Keyword(s):

Frequency Modulation ◽

Unique Feature ◽

Estimation Algorithm ◽

Low Noise ◽

Wide Range ◽

Phase Estimation Algorithm ◽

Balanced Detection ◽

Beam Transmission ◽

Readout Scheme ◽

Monolithic Component

We present a compact optical head design for wide-range and low noise displacement sensing using deep frequency modulation interferometry (DFMI). The on-axis beam topology is realised in a quasi-monolithic component and relies on cube beamsplitters and beam transmission through perpendicular surfaces to keep angular alignment constant when operating in air or in a vacuum, which leads to the generation of ghost beams that can limit the phase readout linearity. We investigated the coupling of these beams into the non-linear phase readout scheme of DFMI and implemented adjustments of the phase estimation algorithm to reduce this effect. This was done through a combination of balanced detection and the inherent orthogonality of beat signals with different relative time-delays in deep frequency modulation interferometry, which is a unique feature not available for heterodyne, quadrature or homodyne interferometry.

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The Statistical Evaluations of Transmission Characteristics, Limits of Ranges and Speeds of Transmission of Information Via the Pulsed Atmospheric Bistatic Optical Channels

Light & Engineering ◽

10.33383/2018-018 ◽

2019 ◽

pp. 97-104

Author(s):

Mikhail V. Tarasenkov ◽

Egor S. Poznakharev ◽

Vladimir V. Belov

Keyword(s):

Communication Systems ◽

Estimation Algorithm ◽

Transmission Characteristics ◽

Radiation Beam ◽

Optical Channels ◽

The Monte Carlo Method ◽

Wide Range ◽

Transmission Of Information ◽

Optical Axes ◽

Visibility Range

The simulation program by the Monte Carlo method of pulse reactions of bistatic atmospheric aerosol-gas channels of optical-electronic communication systems (OECS) is created on the basis of the modified double local estimation algorithm. It is used in a series of numerical experiments in order to evaluate statistically the transfer characteristics of these channels depending on the optical characteristics of an atmosphere plane-parallel model for wavelengths λ = 0.3, 0.5, and 0.9 μm at a meteorological visibility range SM = 10 and 50 km. The results are obtained for a set of basic distances between the light source and the light receiver up to 50 km and for the angular orientations of the optical axes of a laser radiation beam and of the receiving system in a wide range of their values. The dependences of the pulse reactions maximum values over-the-horizon channels of the OECS on the variations of these parameters are established.

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LOW-NOISE SILICON-ON-INSULATOR HALL DEVICES

Fluctuation and Noise Letters ◽

10.1142/s021947750400194x ◽

2004 ◽

Vol 04 (02) ◽

pp. L345-L354 ◽

Cited By ~ 3

Author(s):

Y. HADDAB ◽

V. MOSSER ◽

M. LYSOWEC ◽

J. SUSKI ◽

L. DEMEUS ◽

...

Keyword(s):

Noise Level ◽

Low Voltage ◽

Silicon Layer ◽

Electrical Current ◽

Low Noise ◽

Silicon On Insulator ◽

Technological Parameters ◽

Wide Range ◽

Hall Sensors ◽

Soi Technology

Hall sensors are used in a very wide range of applications. A very demanding one is electrical current measurement for metering purposes. In addition to high precision and stability, a sufficiently low noise level is required. Cost reduction through sensor integration with low-voltage/low-power electronics is also desirable. The purpose of this work is to investigate the possible use of SOI (Silicon On Insulator) technology for this integration. We have fabricated SOI Hall devices exploring the useful range of silicon layer thickness and doping level. We show that noise is influenced by the presence of LOCOS and p-n depletion zones near the edges of the active zones of the devices. A proper choice of SOI technological parameters and process flow leads to up to 18 dB reduction in Hall sensor noise level. This result can be extended to many categories of devices fabricated using SOI technology.

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