The ET LP and AT LP filters from Notch Optics are long-pass optical filters with subtle differences that cater to specific applications. Here’s a comparison:
1. Filter Design and Technology
- ET LP:
- ET (Extended Technology) filters are optimized for higher transmission and steeper edges, meaning they have a more precise cutoff wavelength and superior blocking of shorter wavelengths.
- Designed for applications requiring high performance in terms of signal-to-noise ratio and minimal crosstalk.
- AT LP:
- AT (Advanced Technology) filters are slightly older technology compared to ET. They are less expensive but may have slightly less precise optical performance.
2. Performance Characteristics
- ET LP:
- Higher transmission in the passband (>90-95%).
- Steeper transition from blocked to transmitted wavelengths.
- Better blocking of out-of-band wavelengths (typically OD6 or better).
- AT LP:
- Slightly lower transmission in the passband (around >85-90%).
- Less steep transition compared to ET filters.
- Moderate out-of-band blocking (typically OD4-OD5).
3. Application Suitability
- ET LP:
- Ideal for applications where precise spectral separation is crucial, such as fluorescence microscopy, live cell imaging, or single-molecule studies.
- AT LP:
- Suitable for less demanding applications, such as routine imaging or situations where cost is a significant factor.
4. Price
- ET LP is generally more expensive than AT LP due to its advanced design and superior performance.
5. RET Filters
RET long-pass filters are an advanced subset of the ET (Extended Technology) series, specifically optimized for applications requiring even higher performance in fluorescence imaging. These filters feature:
- Higher Blocking Efficiency: RET filters offer superior out-of-band blocking, typically OD6 or better, ensuring minimal crosstalk and better signal-to-noise ratio.
- Enhanced Transmission: They are designed to maximize light throughput in the passband, often exceeding 95% transmission.
- Sharper Cutoff Edges: RET filters provide exceptionally steep transitions from blocked to transmitted wavelengths, which is crucial for separating closely spaced spectral bands.
- Durable Coatings: These filters often incorporate advanced coatings for higher durability and performance stability under demanding conditions, such as laser-based systems.
Applications: RET filters are ideal for high-precision fluorescence imaging, including multi-color fluorescence microscopy, single-molecule studies, and advanced live-cell imaging. They are often chosen when the highest level of optical performance is critical.
Summary:
If your application requires the best optical performance, go for the ET LP. If cost is a concern and your application is less demanding, the AT LP will suffice.
