ZOLIX BTF+ Broadband Tunable Filter for Supercontinuum Sources

Overview

The ZOLIX BTF+ Broadband Tunable Filter is an optomechanically engineered spectral selection instrument designed specifically for integration with supercontinuum laser sources in advanced photonics laboratories. Operating on the principle of tunable interference filtering—implemented via precision-aligned dielectric thin-film filter elements mounted on a high-stability galvanometric scanning stage—the BTF+ enables continuous, repeatable wavelength selection across the visible spectrum (400–750 nm). Unlike fixed-bandpass or grating-based monochromators, the BTF+ delivers collimated, broadband-filtered output without internal dispersion or beam deviation, preserving spatial coherence and enabling direct coupling into downstream optical paths such as microscopes, spectrographs, or ultrafast pump-probe setups. Its architecture eliminates moving gratings or slit mechanisms, resulting in higher optical throughput, improved long-term wavelength repeatability, and immunity to mechanical hysteresis.

Key Features

• Continuous spectral tuning from 400 nm to 750 nm at up to 40 nm/s scan speed, enabling rapid spectral acquisition in time-resolved experiments
• Adjustable optical bandwidth: user-selectable passband width from 10 nm (narrowband excitation) to 100 nm (broadband illumination), optimized for fluorescence excitation, spectral calibration, or white-light interferometry
• High transmission efficiency (>70% peak) across the entire tuning range, minimizing signal loss and reducing required source power
• Collimated free-space input and output interfaces—compatible with standard Ø25.4 mm or Ø50.8 mm beam paths—eliminating fiber coupling losses and polarization-dependent insertion loss
• USB 2.0 interface with vendor-provided SDK (C/C++, Python, LabVIEW APIs) supporting remote control, script-driven sweeps, and synchronization with external triggers (TTL-compatible)
• Passive thermal stabilization and rigid aluminum housing ensure <±2 nm wavelength accuracy over 8-hour continuous operation at ambient temperatures of 15–30 °C

Sample Compatibility & Compliance

The BTF+ is intended for use with commercially available supercontinuum sources (e.g., NKT SuperK, LEUKOS Easy, FYLA SC400) delivering >100 mW average power in the visible range. It accepts collimated beams with diameters ≤12 mm and divergence <1.5 mrad. No sample interaction occurs—the device functions solely as a spectral conditioning element upstream of the measurement zone. The system complies with IEC 61000-6-3 (EMC emission limits) and IEC 61000-6-2 (immunity requirements), carries CE marking under the EU Machinery Directive 2006/42/EC and Low Voltage Directive 2014/35/EU, and conforms to RoHS 2011/65/EU restrictions on hazardous substances. While not classified as medical or IVD equipment, its stable spectral output supports GLP-aligned optical validation protocols when used in metrology-grade photonic testbenches.

Software & Data Management

ZOLIX provides the BTF+ Control Suite—a cross-platform application (Windows/macOS/Linux) enabling real-time wavelength setting, bandwidth adjustment, and bidirectional sweep programming. All parameter changes are logged with timestamps and saved in CSV-compatible audit trails. The SDK supports integration into custom data acquisition frameworks compliant with FDA 21 CFR Part 11 requirements—including electronic signatures, user access levels, and immutable operation logs—when deployed in regulated QC environments. Firmware updates are delivered via signed binary packages; configuration backups can be exported and version-controlled alongside experimental metadata.

Applications

• Visible-range hyperspectral imaging system calibration using traceable line sources (e.g., Hg/Ar lamps)
• Multi-wavelength excitation in confocal and widefield fluorescence microscopy, particularly for spectral unmixing of fluorophores with overlapping emission profiles
• Time-resolved absorption spectroscopy where tunable probe wavelengths must match transient absorption features between 450–650 nm
• Optical component characterization—including transmittance/reflectance mapping of filters, AR coatings, and dichroics—using calibrated broadband illumination
• Development and validation of computational imaging algorithms requiring controlled, spectrally defined illumination conditions

FAQ

Is the BTF+ compatible with femtosecond supercontinuum sources?
Yes—the optical path contains no dispersive elements that would induce pulse broadening; however, users should verify group delay dispersion (GDD) tolerance of their specific source and apply pre-compensation if necessary.
Can the BTF+ be synchronized with camera frame triggers?
Yes—via TTL input/output ports, enabling hardware-triggered wavelength stepping synchronized to exposure timing in sCMOS or EMCCD acquisitions.
What is the typical warm-up time to achieve specified wavelength accuracy?
Less than 15 minutes after power-on under stable ambient conditions (23 ± 2 °C); no active temperature regulation is required.
Does the BTF+ support automated calibration routines?
Yes—the included software includes guided procedures for wavelength verification using reference spectral lines and optional NIST-traceable calibration kits.
Is vacuum or inert-gas purging supported for UV extension?
No—the current design is optimized for air operation in the 400–750 nm band; UV extension below 400 nm requires separate fused-silica optics and purge-compatible housings (not part of standard BTF+ configuration).