Achromatic optical waveplates based on cellulose nanocrystals

• Cellulose nanocrystals (CNCs) derived from native cellulose can self-assemble into liquid crystals (LCs) and preserve the LC alignment in solid films that are attractive for the preparation of optical materials and devices from bottom-up manufacturing. Birefringent aligned CNC films provide the desired phase retardation for a narrow band of wavelengths due to the intrinsic wavelength-dependent birefringence of CNCs. Here, we produce a 1/4 λ achromatic CNC-based waveplate consisting of three layers of birefringent CNC films with phase retardations and slow axis directions, which are calculated by Jones Matrix, with optimized achromatic properties. Three uniform CNC films are prepared by aligning nematic CNC LCs doped with polyethylene glycol on patterned polydimethylsiloxane substrates. The fabricated achromatic waveplate is characterized by measuring the transmission spectra, and its maximum deviation of phase retardation is around 0.06 for the wavelength range of 460–660 nm. The achromatic performance is improved by one order of magnitude compared with the single birefringent CNC films. Our CNC-based achromatic waveplate has good optical homogeneity, flexibility and can be tailored into arbitrary shape. 

Ämnesord

NATURVETENSKAP  -- Kemi -- Polymerkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Polymer Chemistry (hsv//eng)

Nyckelord

Achromatism

Cellulose nanocrystals

Liquid crystals

Nematics

Waveplates

Birefringence

Cellulose

Cellulose derivatives

Cellulose films

Silicones

Arbitrary shape

Cellulose nanocrystal (CNCs)

Liquid crystals (LCs)

Native cellulose

Optical homogeneity

Phase retardation

Transmission spectrums

Wavelength ranges

Film preparation

Phases

Polysilicones

Retardation

Spectra

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)