Dual-fiber OCT measurements

Elhady, Alaa; Sabry, Yasser M.; Yehia, Mohamed; Khalil, Diaa

doi:10.1117/12.2036485

Cited by 5 publications

(3 citation statements)

References 7 publications

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“…Indeed, a broad range of miniaturized optical devices has been implemented combining one or more of the micro‐optical component together with MEMS actuators. More specifically, variable optical attenuators , optical tunable filters , optical delay lines , grating, Michelson, Mach–Zehnder as well as Fabry–Pérot interferometers , optical cavities , external cavity tunable lasers , Fourier‐transform spectrometry and more recently integrated wide‐angle microscanners and swept laser sources . The special interest in SOI micro‐optical benches is a consequence of their small size, low fabrication cost, self‐alignment and integrability that serve the needs of miniaturized optical instruments.…”

Section: Drie‐fabricated Optical Bench Building‐block Componentsmentioning

confidence: 99%

Monolithic silicon‐micromachined free‐space optical interferometers onchip

Sabry

Khalil

Bourouina

2014

Laser & Photonics Reviews

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The integration of microactuators within a silicon photonic chip gave rise to the field of optical micro‐electro‐mechanical systems (MEMS) that was originally driven by the telecommunication market. Following the latter's bubble collapse in the beginning of the third millennium, new directions of research with considerable momentum appeared focusing on the realization and applications of miniaturized instrumentation in biology, chemistry, physics and materials science. At the heart of these applications light interferometry is a key optical phenomenon, in which miniaturized scanning interferometers are the manipulating optical devices. Monolithic free‐space optical interferometers realized on a silicon chip take advantage of the recent progress in the microfabrication technology that is enabling accurate control of the etching depth, the aspect ratio, the verticality and the curvature of the etched surfaces. The fabrication technology, the library of micro‐optical and mechanical components, the realized architectures and their characterization are described in detail in this review, followed by a discussion of the foreseen challenges.

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Section: Drie‐fabricated Optical Bench Building‐block Componentsmentioning

confidence: 99%

Monolithic silicon‐micromachined free‐space optical interferometers onchip

Sabry

Khalil

Bourouina

2014

Laser & Photonics Reviews

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“…There are two main architectures in the optical MEMS, namely in-plane architecture [ 2 ], where the light propagates from one component to another parallel to the substrate, and out-of-plane architecture [ 3 ], where the light hits the optical component either perpendicular to or with inclination on the substrate. For many applications, such as in optical telecommunication [ 1 ], optical coherence tomography [ 4 ] and on-chip sensing [ 5 ], the light source is connected to the optical MEMS device through a single-mode optical fiber, where the optical beam output from the fiber behaves as a Gaussian beam [ 2 ]. In this case, the propagation can be associated with beam size expansion before detection, leading to optical losses.…”

Section: Introductionmentioning

confidence: 99%

“…This is even more serious in optical MEMS due to the size limit of the optical components [ 6 , 7 ]. Several solutions were introduced as shown in Figure 1 to overcome this challenge, such as the use of a lensed fiber [ 4 ] or an external lens integrated into the system in the form of a graded-index (GRIN) lens or a ball lens [ 6 , 7 , 8 , 9 , 10 , 11 ]. The lensed fiber solution is costly due to the piece-by-piece process of lens formation on the fibers, in addition to the reliability issue to possible fiber tip breakage.…”

Section: Introductionmentioning

confidence: 99%

In-Plane Optical Beam Collimation Using a Three-Dimensional Curved MEMS Mirror

et al. 2017

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The collimation of free-space light propagating in-plane with respect to the substrate is an important performance factor in optical microelectromechanical systems (MEMS). This is usually carried out by integrating micro lenses into the system, which increases the cost of fabrication/assembly in addition to limiting the wavelength working range of the system imposed by the dispersion characteristic of the lenses. In this work we demonstrate optical fiber light collimation using a silicon micromachined three-dimensional curved mirror. Sensitivity to micromachining and fiber alignment tolerance is shown to be low enough by restricting the ratio between the mirror focal length and the optical beam Rayleigh range below 5. The three-dimensional curvature of the mirror is designed to be astigmatic and controlled by a process combining deep, reactive ion etching and isotropic etching of silicon. The effect of the micromachining surface roughness on the collimated beam profile is investigated using a Fourier optics approach for different values of root-mean-squared (RMS) roughness and correlation length. The isotropic etching step of the structure is characterized and optimized for the optical-grade surface requirement. The experimental optical results show a beam-waist ratio of about 4.25 and a corresponding 12-dB improvement in diffraction loss, in good agreement with theory. This type of micromirror can be monolithically integrated into lensless microoptoelectromechanical systems (MOEMS), improving their performance in many different applications.

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