Bragg thickness criterion for intracavity diffraction gratings

Menez, L.; Zaquine, Isabelle; Maruani, A.; Frey, R.

doi:10.1364/josab.19.000965

Cited by 12 publications

(5 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The diffraction phenomena can be described as [ 37 ]

n Λ \sin θ = m λ

where n is the refractive index of the medium, Λ is the grating pitch, θ is the diffraction angle, and m is the diffraction order. At the voltage‐on state (Figure 1d), the refractive index in the initial isotropic state n avg is unchanged at region 1 whereas it changes to the field‐induced refractive index n′ avg ( E ) at region 2 and n″ avg ( E ) at region 3.…”

Section: Theorymentioning

confidence: 99%

Polymer‐Stabilized Monodomain Blue Phase Diffraction Grating

Manda

Heo

Lim

et al. 2020

Adv Materials Inter

View full text Add to dashboard Cite

are self-assembled in a thermodynamically spontaneous way when chirality is about several hundreds of nanometers. LC directors are doubly twisted at this high chirality and self-assembled into a double-twisted cylinder (DTC). The way that the DTCs are stacked determines the symmetry of the BPLC structure, and the lattice length scale in common includes the visible wavelength, which appears as colorful micrographic textures. From an application perspective, a remarkable breakthrough is that polymer-stabilization method is able to extend their narrow temperature range. [6] Dispersion of nanoparticles (organic/inorganic colloids and perovskite quantum dots) or bent-core LCs and 3D confinement of BPLC like microencapsulation is also reported that it can extend the temperature range of BPs. [7][8][9][10] The polymer-stabilized BPLC (PS-BPLC) by in situ photopolymerization is a promising method not only for extending the BP temperature range but also for enhancing their electro-optic performance, such as optical isotropy, [11] selective reflection, [12] less hysteresis, [13] and fast response time. [14] Despite a successful prototyping into a PS-BPLC display, [4] the PS-BPLC has rather shown their possibility of applying to versatile photonic applications such as a diffraction grating, [15] vortex beam ] have been reported by using BPLC materials because these are advantageous for the non-mechanical beam steering. Such results support that BPLC is one of the promising materials to create such novel functional devices. However, the performance of the device is deteriorated by the multidomain structure of BPLCs. For example, the diffraction efficiency decreases significantly. Despite such importance, less attention has been paid to create and study about monodomain BPLCs for diffraction gratings among several studies previously reported. [16,[25][26][27] Some approaches report that, to resolve the unwanted multiple colors from polycrystalline lattice structure, one can adjust the chiral pitch of BPLCs and have the Bragg wavelength shifted far away from the wavelength of device operation. For instance, when the desired wavelength is within the visible region, one can control the chiral pitch to position the Bragg wavelength within UV region. However, this approach is limited to an The structural beauty of liquid crystalline blue phases is attested not only by their colorful optical micrographic textures but also by optical isotropy. More importantly, the homogeneity of the structures influences greatly to the electro-optic properties. In this work, how the lattice orientation in polymerstabilized blue phase liquid crystal (PS-BPLC) diffraction grating affects phase-modulated diffraction efficiency is elaborated. A well-arranged monodomain structure of blue phase is achieved and its diffraction capability is compared with multidomain PS-BPLC. The diffraction efficiency in the zeroth order of monodomain PS-BPLC is improved by 9% compared to that of multidomain structure. In addition, both driving and threshold voltages in m...

show abstract

“…The diffraction phenomena can be described as [ 37 ]

n Λ \sin θ = m λ

Section: Theorymentioning

confidence: 99%

Polymer‐Stabilized Monodomain Blue Phase Diffraction Grating

Manda

Heo

Lim

et al. 2020

Adv Materials Inter

View full text Add to dashboard Cite

show abstract

“…However, their small thicknesses imply a Raman-Nath diffraction regime with several diffraction orders, which limits the maximum power reached in the desired order. Such a drawback was circumvented by placing the holographic material in an asymmetric cavity [6][7][8], and the Bragg operation of the device was obtained, even with a thin recording material [9,10]. Recently, another solution using two-dimensional (2D) photonic crystals was proposed and demonstrated in photopolymers [11].…”

mentioning

confidence: 99%

Efficient Bragg diffraction in thin semiconductor two-dimensional gratings

Zaquine

André

et al. 2008

Opt. Lett.

View full text Add to dashboard Cite

Highly improved diffraction properties are demonstrated in a two-dimensional [2D] grating consisting of a transmission grating optically recorded in a semiconductor one-dimensional photonic crystal (1D-PC). Near unity internal diffraction efficiency, high wavelength selectivity, and Bragg diffraction regime operation are demonstrated when the read beam is set at Bragg incidence on the transmission grating while its wavelength corresponds to the band edge of the 3 microm thick 1D-PC. When the 2D grating is grown on a Bragg mirror, a single diffracted beam is obtained, which makes the device promising for optical signal processing.

show abstract

“…4 Moreover, such a device was shown to exhibit a Bragg diffraction regime in a very thin nonlinear medium. 5 Diffraction efficiencies larger than unity were predicted for refractive index gratings placed inside amplifying Fabry-Perot cavities. 6 Such devices are very interesting since they provide the large fan-out values often required for applications to optical signal processing.…”

mentioning

confidence: 99%

Intracavity gain gratings

Moreau

Zaquine

et al. 2007

Opt. Lett.

Self Cite

View full text Add to dashboard Cite

Intracavity gain gratings are theoretically demonstrated to exhibit diffraction efficiencies that are 100 times larger than unity at pump powers substantially below the lasing threshold. Experiments performed using a Nd:YVO4 microlaser pumped below threshold by two interfering Ti:sapphire laser beams are described. Huge enhancement of the diffraction efficiency (5000X) and a large increase of the angular selectivity (10X) are demonstrated despite the angular reduction of the Fabry-Perot cavity finesse. Much better results are expected using gain gratings with larger areas or thinner cavities such as vertical cavity surface-emitting lasers. Such large fan-out values could be very interesting for applications to optical signal processing.

show abstract

Bragg thickness criterion for intracavity diffraction gratings

Cited by 12 publications

References 14 publications

Polymer‐Stabilized Monodomain Blue Phase Diffraction Grating

Polymer‐Stabilized Monodomain Blue Phase Diffraction Grating

Efficient Bragg diffraction in thin semiconductor two-dimensional gratings

Intracavity gain gratings

Contact Info

Product

Resources

About