LED source interferometer for microscopic fringe projection profilometry using a Gates’ interferometer configuration

3D Reconstruction From Structured-Light Profilometry With Dual-Path Hybrid Network

“…There are also many research improvements on lighting hardware and structuredlight pattern design nowadays. In [11], for the application of structured-light profilometry on a microscopic scale, they present a Gates' interferometer configuration with an LED source to project a structured-light pattern without speckle noise and a very long field depth, the system can obtain excellent sinusoidal structuredlight on the surface of microscopic objects. Linear structured-light patterns cannot uniquely represent the lateral displacement caused by objects with surface discontinuities, [12] proposes using a radially symmetric circular structured-light pattern as the structured-light pattern for accurate unambiguous surface profiling of sudden height-discontinuous objects, experimental results prove that the proposed method can be applied for the reconstruction of objects with 4 times higher dynamic range and even at much lower structured-light frequencies.…”

Digital Holographic Microscopy as Identifier of Ultrafine Particles Emitted during Fused Deposition Modelling

“…The experimental optical arrangement used in this study was a Gates interferometer, as shown in Figure 3, which has previously been used in investigations by the authors [30,32,33]. A 5 mW laser diode with a wavelength (λ) of 640 nm was used as the illumination source.…”

“…On the other hand, the camera used to capture the micro-holograms was a 1024 × 1328-pixel monochrome StingrayTM with a pixel size of 6.4 µm × 6.4 µm with an 8-bit depth. For more details about how the Gates interferometer works, consult the following references [32,33].…”

“…monochrome StingrayTM with a pixel size of 6.4 μm × 6.4 μm with an 8-bit depth. For more details about how the Gates interferometer works, consult the following references [32,33]. In Figure 4a it is possible to observe a hologram captured by the system, while in Figure 4b a photograph of the sample is presented under white light illumination.…”

“…In addition, it is important to mention that the maximum object dimensions that could be analyzed by the proposed equipment arrangement will depend on two factors, being the size of the beam splitter cube and the camera sensor. In other words, the larger the sensor and the beam splitter cube, the larger it would be the size of the object capable of being analyzed [33]. The Figure 4a shows an experimental digital hologram obtained by the optical setup proposed of the Figure 3.…”