Parameters and Specifications of FLUORESCENCE FILTERS

FLUORESCENCE FILTERS (fluorescence filters) parameter indicators (technical specifications) 

UltraOpto FLUORESCENCE FILTERS are specifically designed for applications such as fluorescence imaging, fluorescence detection, biological analysis, and microscope systems. The core parameters directly determine the accuracy of fluorescence signal collection and the anti-interference capability. The following are the standardized core parameter indicators, covering both general mass production models and customized parameter ranges, clearly adapting to the needs of different application scenarios. 

I. Core Optical Parameters (Key Performance Indicators) 

Operating Wavelength 

Core parameters determine the fluorescence excitation and emission wavelengths that the filter is compatible with, and they are divided into general bands and custom bands: 

General range: 

350nm - 1100nm (covering ultraviolet, visible light, and near-infrared regions); 

Fine-tuning adaptation: excitation filter (Ex) 350-550nm, emission filter (Em) 400-650nm, dichroic filter (Dichroic) 450-700nm; 

Customization range: 

Customizable within the 200nm-2000nm band as required, precisely matching the excitation/emission wavelengths of specific fluorescent dyes (such as FITC, TRITC, DAPI). 

2. Transmittance 

The measurement of a filter's ability to transmit light at the target wavelength directly affects the intensity of the fluorescence signal. 

Emission filter (Em): 

The transmission rate T of the target band is ≥ 90% (≥ 95% for high-end customized models), ensuring efficient transmission of the fluorescence signal. 

Excitation filter (Ex): 

The target band transmission rate T ≥ 85%, balancing the utilization rate of excitation light and signal purity; 

Error range: The transmission rate deviation of products in the same batch is ≤ ±3%, ensuring batch consistency. 

3. Blocking Depth 

The core anti-interference index measures the filter's ability to block non-target wavelength light, preventing stray light interference. 

General standard: The cut-off depth OD of non-target bands is ≥ 4 (i.e., the blocking rate is ≥ 99.99%). 

High-end customization: For biological imaging and low-background detection scenarios, the cut-off depth OD ≥ 6 (blocking rate ≥ 99.9999%). 

Coverage range: 200nm - 2500nm, ensuring no stray light leakage across the entire spectrum. 

4. Full Width at Half Maximum (FWHM) 

The narrower the half-width at half-maximum of a filter, the more precise its wavelength selection. 

General range: FWHM = 10 - 50 nm, suitable for conventional fluorescence detection. 

Precise Customization: High-resolution imaging scenarios, FWHM can be customized to 5-10nm, precisely separating adjacent fluorescence bands; 

Deviation control: The half-width deviation is ≤ ±2nm to ensure the accuracy of wavelength selection. 

5. Extinction Ratio (ER) 

For polarization-type fluorescence filters, the ability to separate polarization states is measured as follows: 

General standard: ER ≥ 1000:1; 

High-end model: ER ≥ 5000:1, suitable for applications such as polarized fluorescence imaging and quantum fluorescence detection. 

II. Geometric Parameters (Adaptation and Installation Indicators) 

1. Dimensions 

General sizes: Circular (Φ12.5mm, Φ25mm, Φ50mm), Square (25mm×25mm, 50mm×50mm) 

Customized size: Circular shapes with diameters ranging from Φ5mm to Φ100mm and square shapes with dimensions from 10mm×10mm to 100mm×100mm can be customized as required. Thickness ranges from 0.3mm to 5mm. 

Dimensional tolerance: Length/diameter tolerance ±0.1mm, thickness tolerance ±0.02mm, to ensure proper installation fit. 

2. Surface Figure (Surface Shape Accuracy) 

General standard: λ/4 @ 632.8nm; 

High-end customization: λ/[email protected], suitable for high-resolution fluorescence microscopes and precise spectral detection systems; 

Surface roughness: Ra ≤ 0.2 nm, to avoid light scattering and its impact on signal purity. 

3. Parallelism 

General standard: ≤ 0.1 arcmin; 

High-end requirement: ≤ 0.05 arcmin, to prevent light deviation and ensure image clarity. 

III. Environmental and Reliability Parameters (Long-Term Usage Indicators) 

1. Operating Temperature

General range: -40℃ to 85℃, suitable for conventional laboratory and industrial testing environments. 

Special customization: The temperature range can be extended to -60℃ to 120℃ for high and low temperature scenarios, ensuring stable performance in extreme environments. 

2. Humidity Resistance (Resistance to Humidity) 

After being placed in an environment with a constant temperature of 85℃ and a constant humidity of 85% for 500 hours, there was no peeling of the film layer or drift in transmittance, meeting the usage requirements in the humid environment of biological laboratories. 

3. Laser-induced damage threshold (LIDT) 

Continuous wave (CW): ≥ 10 W/cm² @ 532 nm; 

Pulse: ≥100mJ/cm² @ 1064nm (10ns), suitable for high-power fluorescence excitation scenarios, preventing film layer burnout. 

4. Coating Adhesion 

The film layer passed the ISO 15184 standard tape test without peeling or flaking. After the wipe test, the transmittance change was ≤1%, ensuring no performance degradation during long-term use. 

IV. Customized Parameter Description 

UltraOpto can customize the following special parameters based on the specific application scenarios of customers: ① Excitation/emission bands and half-widths matched with specific fluorescent dyes; ② Customization of high cut-off depth (OD≥7) and high transmittance (T≥98%); ③ Adaptation to irregular shapes, special thicknesses and polarization states; ④ Special environmental adaptation parameters such as high temperature resistance and corrosion resistance, fully meeting the needs of different scenarios such as fluorescence imaging, biological detection, and industrial fluorescence detection.