Rainbow Photonics TeraKit Series Time-Domain Terahertz Imaging Systems

Overview

Rainbow Photonics TeraKit Series Time-Domain Terahertz (THz-TDS) Imaging Systems are engineered for high-fidelity, coherent detection and spatially resolved spectroscopic analysis in the 0.1–11 THz range. Based on optical rectification and electro-optic sampling principles, these systems leverage ultrafast femtosecond laser pulses to generate and detect broadband THz radiation with phase-resolved capability. The modular architecture supports both free-space and fiber-coupled configurations, enabling seamless integration into existing ultrafast laser laboratories. Designed for fundamental research and applied metrology, the TeraKit platforms deliver quantitative amplitude and phase information—essential for dielectric property mapping, layered structure characterization, and non-destructive evaluation of low-conductivity materials.

Key Features

• Modular THz-TDS platform with interchangeable emitters (DAST, OH1, DSTMS) optimized for distinct spectral bandwidths and phase-matching windows (1200–1700 nm)
• Coherent time-domain detection enabling simultaneous extraction of absorption coefficient, refractive index, and complex permittivity without Kramers-Kronig transformation
• Precision motorized delay line with sub-5-fs temporal resolution and <1 µm positional repeatability for high-fidelity waveform acquisition
• Scanning stage with 100 mm × 100 mm travel range, programmable step resolution down to 1 µm, and bidirectional linear encoding
• Optimized optical layout accommodating standard Ti:sapphire (700–1000 nm), Yb-fiber (1030–1080 nm), or Er-fiber (<1600 nm) laser sources with pulse durations ≤ 80 fs
• Low-noise, lock-in amplified detection electronics with dynamic range > 80 dB and shot-noise-limited sensitivity at 1 THz

Sample Compatibility & Compliance

The TeraKit systems accommodate a broad class of non-metallic, non-aqueous samples—including polymers, pharmaceutical tablets, composite laminates, semiconductor wafers, and cultural heritage artifacts—without requiring vacuum or cryogenic environments. Sample chambers support ambient, dry-air, or nitrogen-purged operation to minimize atmospheric water vapor absorption (particularly critical above 0.5 THz). All hardware and firmware comply with CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU). Data acquisition workflows support audit-trail generation and user-access controls aligned with GLP and ISO/IEC 17025 laboratory quality management frameworks.

Software & Data Management

Acquisition and analysis are managed via TeraSoft—a cross-platform application built on Qt and Python-based scientific libraries (NumPy, SciPy, Matplotlib). TeraSoft provides real-time waveform visualization, automated baseline correction, Fourier-transform spectral extraction, and pixel-wise parameter mapping (e.g., peak amplitude, time-of-flight, spectral centroid). Export formats include HDF5 (with metadata schema compliant with NeXus standards), CSV, and MATLAB .mat. For regulated environments, optional 21 CFR Part 11-compliant modules provide electronic signatures, change history logging, and role-based access control. Raw time-domain data retains full phase information, enabling post-acquisition reprocessing using custom algorithms or third-party packages such as THzTools or TeraView’s TeraPulse SDK.

Applications

• Non-destructive testing (NDT) of multilayer polymer films, paint coatings, and adhesive bonds in aerospace composites
• Quantitative crystallinity mapping in pharmaceutical tablet formulations (e.g., polymorph identification, API distribution)
• Carrier dynamics and mobility profiling in 2D materials (graphene, transition metal dichalcogenides) under photoexcitation
• Time-resolved THz spectroscopy of ultrafast spin and charge transfer processes in perovskite photovoltaics
• Cultural heritage analysis: subsurface defect detection in historical manuscripts, fresco stratigraphy, and varnish layer thickness quantification
• Security screening: concealed object discrimination based on spectral fingerprinting and refractive index contrast

FAQ

What laser specifications are required to operate the TeraKit systems?
A mode-locked femtosecond laser with average power ≥ 100 mW, pulse duration ≤ 80 fs, and repetition rate between 50–100 MHz is recommended. Central wavelength must fall within the phase-matching window of the selected emitter crystal (e.g., 1300–1600 nm for DAST).
Can the system be upgraded from TeraKit-D to TeraKit-DS?
Yes—TeraKit platforms are designed with mechanical and electrical backward compatibility; emitter modules, delay lines, and detector mounts follow standardized kinematic interfaces for field-upgradable configuration changes.
Is real-time imaging supported?
Standard operation uses point-by-point raster scanning. Real-time video-rate imaging (≥ 30 fps) requires optional high-speed galvanometric scanning optics and parallel detection schemes, available upon consultation.
Does the system support polarization-resolved measurements?
Yes—integrated half-wave plates, wire-grid polarizers, and EO crystal orientation allow full Stokes parameter acquisition for birefringence and dichroism mapping.
What calibration standards are included?
NIST-traceable polyethylene reference foils (100–500 µm thick) are supplied for amplitude and time-zero calibration; refractive index validation is performed using fused silica and silicon wafers with certified thicknesses.