MiXran Meg1108 Long-Wave Pass Optical Filter

Overview

The MiXran Meg1108 is a high-performance, precision thin-film interference long-wave pass (LWP) optical filter engineered for demanding spectral separation tasks in research-grade optical systems. Designed using multi-layer dielectric coating technology on UV-grade fused silica substrates, the Meg1108 transmits wavelengths longer than its specified cutoff edge while providing deep, broadband suppression of shorter-wavelength radiation. Its steep transition slope (typical edge sharpness 90% across the passband), and exceptional out-of-band blocking (OD ≥6 from 200 nm to cutoff −15 nm) make it suitable for fluorescence microscopy, Raman spectroscopy, laser line cleanup, multiband imaging, and photonic sensor conditioning. Unlike absorptive filters, the Meg1108 operates via constructive and destructive interference—ensuring minimal thermal load, polarization insensitivity (for normal incidence), and long-term environmental stability under controlled laboratory conditions.

Key Features

• Precision-tuned center wavelength options spanning 400 nm to 1100 nm in 25 nm increments, enabling exact spectral alignment with common excitation sources (e.g., 405 nm diodes, 532 nm Nd:YAG, 785 nm Raman lasers, or 1064 nm IR systems).
• High-transmission passband extending continuously from cutoff to 2000 nm—ideal for NIR and SWIR applications requiring extended spectral coverage.
• Robust UV-grade fused silica substrate with ≤3 arcsec parallelism and 60-40 surface quality, minimizing wavefront distortion and ensuring compatibility with collimated beam paths and high-NA objectives.
• Hard-coated dielectric stack deposited via ion-assisted e-beam evaporation, delivering excellent adhesion, humidity resistance (per MIL-C-48497A), and resistance to cleaning solvents including isopropanol and acetone.
• Three standardized clear apertures: 12.5 mm (for compact OEM modules), 25 mm (for standard lens tubes and filter wheels), and 50 mm (for large-beam or imaging systems), all with ≥90% clear aperture specification.
• Compliant with ISO 10110-7 for optical coating specifications and tested per ISO 9211-4 for spectral performance verification using calibrated double-monochromator spectrophotometers.

Sample Compatibility & Compliance

The Meg1108 is compatible with standard SM-threaded filter mounts (e.g., SM1, SM2), cage systems (e.g., Thorlabs 30 mm and 60 mm), and custom optomechanical housings. It is designed for use in ambient laboratory environments (20–25 °C, 40–60% RH) and exhibits no measurable shift in cutoff wavelength under typical thermal cycling (±5 °C). The filter meets RoHS Directive 2011/65/EU for hazardous substance restrictions and is manufactured in an ISO 9001-certified facility. While not classified as medical or aerospace-grade hardware, its performance traceability supports GLP-aligned documentation workflows when integrated into validated analytical instruments (e.g., HPLC-UV detectors, confocal microscope filter sets, or portable spectrometers).

Software & Data Management

Spectral transmission data for each Meg1108 unit is provided in ASCII-compatible .csv format upon request, containing wavelength (nm) vs. %T at 1 nm resolution from 200 nm to 2000 nm. These datasets are compatible with common optical design software (Zemax OpticStudio, CODE V, FRED) and analysis platforms (MATLAB, Python SciPy, OriginLab). For integration into automated systems, the product identifiers (e.g., GLWPH-650-D25) follow a deterministic nomenclature: GLWPH = Long-Wave Pass Hybrid; XXX = CWL in nm; DXX = diameter in mm. No proprietary drivers or firmware are required—physical installation only.

Applications

• Fluorescence lifetime imaging (FLIM) and time-gated detection, where precise rejection of excitation light below the Stokes shift is critical.
• Raman spectroscopy pre-filtering to eliminate Rayleigh scatter and protect sensitive CCD/CMOS detectors.
• Multispectral imaging systems requiring band-defining elements in push-broom or snapshot architectures.
• Laser safety interlocks and beam diagnostics in Class IV laser enclosures (e.g., blocking 1064 nm pump while transmitting 1550 nm signal).
• Calibration reference sets for spectroradiometers and hyperspectral camera validation protocols (per ASTM E308 and CIE S 026).
• Photobiomodulation and dermatology device development, where controlled NIR transmission profiles influence tissue penetration depth modeling.

FAQ

What is the damage threshold specification for the Meg1108?
The filter is rated for >5 J/cm² at 1064 nm, 10 ns pulse width, 10 Hz repetition rate, measured at normal incidence on coated surface. Continuous-wave power handling is limited by substrate absorption and should not exceed 1 W/cm² without active cooling.

Can the Meg1108 be used at non-normal angles of incidence?
Yes, but angular tuning shifts the cutoff toward shorter wavelengths (~0.5 nm per degree for s-polarized light at 500 nm). For applications requiring stable edge position, mounting in kinematic cells with angular repeatability <0.1° is recommended.

Is there batch-to-batch spectral variation?
Spectral uniformity is maintained within ±2 nm CWL tolerance and ±3% peak transmission across production lots. Certificate of Conformance includes measured transmission curve for each shipped unit.

Do you offer custom diameters or coatings outside the listed CWL range?
Custom configurations—including diameters up to 75 mm, CWL from 350 nm to 1200 nm, and hybrid edge slopes—are available under NRE-supported engineering engagement. Contact technical sales for feasibility assessment.

How should the Meg1108 be cleaned?
Use dry nitrogen purge first. If contamination persists, apply spectroscopic-grade methanol or isopropanol with lint-free optical tissue (e.g., Whatman Puradisc) using radial motion. Avoid ultrasonic baths or abrasive cleaners.