Simple, adjustable beam splitting element for differential interferometers based on photoelastic birefringence of a prismatic bar

AbstractElectron and ion beams are indispensable tools in numerous fields of science and technology, ranging from radiation therapy to microscopy and lithography. Advanced beam control facilitates new functionalities. Here, we report the guiding and splitting of charged particle beams using ponderomotive forces created by the motion of charged particles through electrostatic optics printed on planar substrates. Shape and strength of the potential can be locally tailored by the lithographically produced electrodes’ layout and the applied voltages, enabling the control of charged particle beams within precisely engineered effective potentials. We demonstrate guiding of electrons and ions for a large range of energies (from 20 to 5000 eV) and masses (from 5 · 10−4 to 131 atomic mass units) as well as electron beam splitting for energies up to the keV regime as a proof-of-concept for more complex beam manipulation.

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Development of a Compound Speckle Interferometer for Precision Three-Degree-of-Freedom Displacement Measurement

Sensors ◽

10.3390/s21051828 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1828

Author(s):

Hung-Lin Hsieh ◽

Bo-Yen Sun

Keyword(s):

Speckle Interferometry ◽

Degree Of Freedom ◽

Heterodyne Interferometry ◽

Beam Splitting ◽

Speckle Interferometer ◽

Real World Applications ◽

Three Degree Of Freedom ◽

Contact Displacement ◽

Displacement Measurements ◽

Measurement Capabilities

In this study, a compound speckle interferometer for measuring three-degree-of-freedom (3-DOF) displacement is proposed. The system, which combines heterodyne interferometry, speckle interferometry and beam splitting techniques, can perform precision 3-DOF displacement measurements, while still having the advantages of high resolution and a relatively simple configuration. The incorporation of speckle interferometry allows for non-contact displacement measurements by detecting the phase of the speckle interference pattern formed from the convergence of laser beams on the measured rough surface. Experiments were conducted to verify the measurement capabilities of the system, and the results show that the proposed system has excellent measurement capabilities suitable for future real-world applications.

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Compact Photonic Crystal Polarization Beam Splitter Based on the Self-Collimation Effect

Photonics ◽

10.3390/photonics8060198 ◽

2021 ◽

Vol 8 (6) ◽

pp. 198

Author(s):

Geyu Tang ◽

Huamao Huang ◽

Yuqi Liu ◽

Hong Wang

Keyword(s):

Optical Communications ◽

Beam Splitter ◽

Extinction Ratio ◽

Polarized Light ◽

The Self ◽

Polarization Beam Splitter ◽

Optical Interconnection ◽

Beam Splitting ◽

Beam Splitters ◽

Polarization Extinction Ratio

We propose a new compact polarization beam splitter based on the self-collimation effect of two-dimensional photonic crystals and photonic bandgap characteristics. The device is composed of a rectangular air holes-based polarization beam splitting structure and circular air holes-based self-collimating structure. By inserting the polarization beam splitting structure into the self-collimating structure, the TE and TM polarized lights are orthogonally separated at their junction. When the number of rows in the hypotenuse of the inserted rectangular holes is 5, the transmittance of TE polarized light at 1550 nm is 95.4% and the corresponding polarization extinction ratio is 23 dB; on the other hand, the transmittance of TM polarized light is 88.5% and the corresponding polarization extinction ratio is 37 dB. For TE and TM polarized lights covering a 100 nm bandwidth, the TE and TM polarization extinction ratios are higher than 18 dB and 30 dB, respectively. Compared with the previous polarization beam splitters, our structure is simple, the size is small, and the extinction ratio is high, which meets the needs of modern optical communications, optical interconnection, and optical integrated systems.

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