Emerging liquid crystal waveguide technology for low SWaP active short-wave infrared imagers

Keller, Sean; Lynch, Ted; Davis, Sumner P.; Rommel, Scott D.; Pino, Juan

doi:10.1117/12.2076835

Cited by 3 publications

(8 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the previous work (12,13), the electrode patterns to drive the liquid crystal layer are pre-designed and fabricated, the beam steering function was realized mainly through varying the applied voltage. Since the electrode patterns are fixed after the fabrication, this brings several limitations to develop other approaches to drive the beam steering device in a continuous manner.…”

Section: 4tfts Based Beam Steering Device Architecture and Drivingmentioning

confidence: 99%

“…(2)(3)(4) Due to the existence of physical momentum, such mechanical laser sweeping method has its natural limitations in several aspects. (2,5,6) Therefore, alternative solutions are highly demanded. Among those new rising technologies (7)(8)(9)(10)(11), liquid-crystal-based beam steering devices have been demonstrated and believed to be rather promising for the commercialization in terms of its cost and technology compatibility.…”

Section: Introductionmentioning

confidence: 99%

“…Among those new rising technologies (7)(8)(9)(10)(11), liquid-crystal-based beam steering devices have been demonstrated and believed to be rather promising for the commercialization in terms of its cost and technology compatibility. (5,12,13) From the work of S.R. Davis et al, (13) a prototype with such unique architecture was firstly exhibited, as illustrated in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

“…The working principle of such device results in several merits, namely, faster scanning rate (more than 10 kHz), compatible with the existing display industry. (5,6,13,14) Figure 1. Crossection view of beam steering device based on liquid crystal cladding layer.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

5.4: An active approach of TFT matrix controlling for liquid crystal cladding based beam steering device

Liu

Lou

Qiu

2021

Symp Digest of Tech Papers

View full text Add to dashboard Cite

Currently, Light Detection and Ranging (LiDAR) system has been widely used in various applications. However, the commercialized solution can hardly meet the rising demands, especially in autonomous driving vehicles. To further improve the laser scanning rate, life‐time and possibly lowering the cost, the main technology trend is through replacing the mechanical rotational parts with solid structures. Among those new emerging technology approaches, liquid‐crystal‐based beam steering device is one of the promising routes. In this work, for the first time in reports, the physics of such liquid‐crystal‐based devices are thoroughly explained through numerical simulation and modeling. In addition, a new device architecture with thin film transistors (TFTs) matrix and its driving methods are also introduced. With the improved driving electrodes (using TFTs panel), a wide beam steering angle (±42°) can be achieved. Meanwhile, the device remains as a reprogrammable piece even after fabrication, leaving enough room for further upgrades in terms of driving algorithm.

show abstract

Section: 4tfts Based Beam Steering Device Architecture and Drivingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

5.4: An active approach of TFT matrix controlling for liquid crystal cladding based beam steering device

Liu

Lou

Qiu

2021

Symp Digest of Tech Papers

View full text Add to dashboard Cite

show abstract

“…Using the LC as a cladding layer and targeting wavelength regimes with low scattering and absorption helps mitigate these losses, which has led to the commercial development of tunable LC waveguides in the short-wave IR (SWIR) [12,16]. Prototype devices have been developed in the near IR (NIR) [28] and mid-wave IR (MWIR) [17], but LC losses in these regimes can already be prohibitive. A comprehensive analysis of the interaction between the confined electric field and the LC can lead to more efficient design and is crucial to the continued development of this technology outside the SWIR.…”

Section: Introductionmentioning

confidence: 99%

Propagating transverse electric and transverse magnetic modes in liquid crystal-clad planar waveguides

et al. 2019

View full text Add to dashboard Cite

In a planar dielectric waveguide, weak confinement of a propagating mode in a high index core leads to a measurable evanescent interaction with the cladding. In this work, we study the effect of a reorientable anisotropic cladding on the behaviour of Transverse Electric (TE) and Transverse Magnetic (TM) mode polarisations using a liquid crystal (LC)-clad waveguide architecture. The polarised evanescent field of a guided mode interacts with a voltage-tunable birefringent LC cladding to deflect an out-coupled beam. Experimental measurements are coupled with a theoretical framework and show good consistency with simulation results. We isolate the effect of mode confinement by changing the thickness of the high index core. Interactions between the LC index ellipsoid and the mode polarisation are probed by changing the initial alignment of the LC. Finally, we examine the difference in deflection between TE and TM modes, which incorporates both a change in mode confinement and a difference in LC index components.

show abstract

End-fire silicon optical phased array with half-wavelength spacing

2017

View full text Add to dashboard Cite

We demonstrate a one-dimensional optical phased array on an integrated silicon platform for operation at 1.55 µm. Light is emitted end-fire from the chip edge where the waveguides are terminated. The innovative design and high confinement afforded by the silicon waveguides enables λ/2 spacing (775-nm pitch) at the output. Steering is achieved by inducing a phase shift between the waveguides via integrated thermo-optic heaters. The device forms a beam with a FWHM angular width of 17°, and we demonstrate beam steering over a 64° range.A multitude of applications depend on the ability to quickly and accurately steer a laser beam, ranging from fiber endoscopes in biological imaging to LiDAR scanning in large-scale landscape surveying and autonomous automobile navigation. In addition, high-speed beam steering has the potential to impact a host of new technologies from free space optical communications to next-generation projectors. The conventional approaches to realizing optical beam steering are mechanical in nature and require bulky motors and gimbals to physically move the entire laser system, or alternatively tilt-mirrors through galvanometer-based or micromechanical devices. Mechanical systems are fundamentally limited in speed by their inertia. Commercial galvanometer tilt-mirror devices have maximum steering speeds of approximately 10 kHz, whereas the fastest MEMS devices can reach up to 420 kHz [1]. Both types of steering systems can be limited in range as well, with most systems subtending less than 40° total. These limitations have recently prompted the development of nonmechanical beam steering techniques based on integrated optical phased arrays (OPAs) in silicon photonic platforms, which steer by forming a beam from the interference of multiple phase-controlled optical emitters.

show abstract

Emerging liquid crystal waveguide technology for low SWaP active short-wave infrared imagers

Cited by 3 publications

References 8 publications

5.4: An active approach of TFT matrix controlling for liquid crystal cladding based beam steering device

5.4: An active approach of TFT matrix controlling for liquid crystal cladding based beam steering device

Propagating transverse electric and transverse magnetic modes in liquid crystal-clad planar waveguides

End-fire silicon optical phased array with half-wavelength spacing

Contact Info

Product

Resources

About