EHC KCRK-07 Cholesteric Liquid Crystal Cell Holder
| Brand | EHC |
|---|---|
| Origin | Japan |
| Model | KCRK-07 |
| Type | Precision Alignment Cell Fixture for Cholesteric Pitch Characterization |
| Application | Optical Metrology of Chiral Nematic Liquid Crystals |
Overview
The EHC KCRK-07 is a precision-engineered liquid crystal cell holder designed specifically for the optical characterization of cholesteric (chiral nematic) liquid crystal materials. It consists of two optically flat, high-transmittance glass substrates—typically borosilicate or fused silica—coated with transparent conductive layers (e.g., ITO) and subjected to controlled unidirectional alignment treatments (e.g., rubbed polyimide or photoalignment). These substrates are assembled with a precisely defined, sub-micron-scale twist angle (typically 0.1°–2.0°), establishing a well-defined pretilt and helical axis orientation across the interstitial gap. This geometry enables reproducible measurement of the selective reflection band, pitch length (P), temperature-dependent pitch variation (dP/dT), and electric-field-induced pitch modulation—critical parameters in the development of tunable filters, reflective displays, circular polarizers, and chiral photonic sensors.
Key Features
- Ultra-stable mechanical assembly with thermally matched glass spacers and UV-curable epoxy sealing, minimizing drift during thermal cycling (−20 °C to +80 °C)
- Controlled cell gap tolerance of ±0.05 µm, verified via interferometric thickness mapping
- Alignment uniformity < 0.3° RMS across active area (typ. 15 × 15 mm optical aperture)
- Integrated gold-plated edge electrodes for low-resistance, non-polarizing DC/AC biasing (up to 100 Vpp, 1 kHz)
- Compatibility with standard optical mounts (e.g., SM1-threaded cage systems, kinematic baseplates)
- Hermetically sealed cavity option available for inert-atmosphere operation (N2 or Ar purging)
Sample Compatibility & Compliance
The KCRK-07 accommodates standard 25 × 25 mm or custom-cut glass substrates with thicknesses of 0.7–1.1 mm. It supports both planar and homeotropic alignment configurations, provided substrate surface treatments are applied prior to cell assembly. The device complies with ISO 10110-7 (optical element surface quality) and JIS C 5602 (liquid crystal display component testing standards). Its construction avoids outgassing polymers and uses only vacuum-compatible adhesives, making it suitable for integration into cleanroom-compatible optical benches and environmental chambers. While not a standalone measurement instrument, the KCRK-07 is routinely deployed in setups conforming to ASTM E2847 (standard practice for characterizing liquid crystal electro-optic response) and supports GLP-aligned experimental protocols when paired with calibrated spectrophotometers or laser-based interferometric pitch analyzers.
Software & Data Management
As a passive optical cell platform, the KCRK-07 does not include embedded firmware or proprietary software. However, it is fully interoperable with industry-standard instrumentation control environments—including LabVIEW, Python (via PyVISA or NI-VISA), MATLAB Instrument Control Toolbox, and Keysight PathWave. When integrated into automated optical characterization workflows, users commonly implement audit-trail logging for temperature setpoints, voltage waveforms, spectral acquisition timestamps, and environmental chamber conditions. Such configurations can be validated against FDA 21 CFR Part 11 requirements for electronic records and signatures when supported by appropriate system validation documentation and role-based access controls.
Applications
- Determination of helical pitch length (P) via selective reflection peak wavelength (λ = n·P, where n is average refractive index)
- Quantification of pitch temperature coefficient (TCP) in thermochromic cholesteric formulations
- Investigation of electric-field-induced unwinding and pitch compression in polymer-stabilized cholesterics
- Calibration reference for Mueller matrix polarimetry and Bragg spectroscopy systems
- Development and screening of chiral dopants for wide-bandgap or multi-domain pitch tuning
- Teaching laboratory use in advanced soft matter physics and photonic crystal courses
FAQ
What is the typical cell gap range supported by the KCRK-07?
Standard configurations offer nominal gaps of 5 µm, 10 µm, and 20 µm, with custom gaps from 3 µm to 50 µm available upon request.
Can the KCRK-07 be used under vacuum or controlled gas atmosphere?
Yes—optional hermetic sealing with Viton O-rings and stainless-steel flange interfaces enables operation down to 10−5 mbar or within regulated N2/Ar gloveboxes.
Is the alignment direction marked on the cell?
Each unit includes laser-etched alignment reference marks (±0.1° angular accuracy) adjacent to the optical aperture, traceable to NIST-calibrated rotation stages used during fabrication.
Does EHC provide alignment verification data with each shipment?
Yes—certified alignment uniformity maps and interferometric gap profiles are supplied as PDF reports with every KCRK-07 unit.
Are replacement substrates or re-alignment services available?
EHC offers substrate refurbishment, re-coating (ITO/sputtered metal), and re-alignment services through its Yokohama technical center, subject to minimum batch requirements.
