Skip to content 
678nm Long Pass Dichroic Mirror
678nm Long Pass Dichroic Mirror is an optical beamsplitter designed to reflect wavelengths shorter than 678nm and transmit longer than 678nm. Coligh manufactures dichroic mirror
It has key features below:
- Cut on wavelength 678nm
- High reflectivity and high transmission
- AOI: 45deg
- Hard dielectric coating
- Fused silica substrate
- Suitable for Red/NIR fluorescence seperation
Products Categories
Get A Free Quote
678nm Long Pass Dichroic Mirror With Hard-Coated Dielectric Description
678nm Long Pass Dichroic Mirror is a high-performance optical spectroscope designed for precise separation of excitation light and fluorescence emission light in the red and near-infrared bands.
- This dichroic mirror has a transmittance of more than 90% for fluorescence signals with wavelengths >678nm, ensuring maximum emission light intensity. It also effectively reflects excitation light with wavelengths below 678nm, with a reflectivity of more than 98%, reducing the interference of excitation light on the detection signal. By effectively suppressing the leakage of excitation light, the signal-to-noise ratio of red and near-infrared fluorescence signals is significantly enhanced, and clearer and higher-contrast images are obtained.
- We use hard coating technology to make the film more stable and durable, capable of using high-power lasers and complex experimental environments, ensuring stable optical performance in long-term use, reducing maintenance and replacement frequency, and reducing experimental costs.
- It is widely used in confocal microscopes, flow cytometers, FRET experiments, in vivo imaging and multi-channel fluorescence imaging systems, supporting complex multi-color labeling schemes.
678nm Long Pass Dichroic Mirror Technical Datasheet
| Parameter | Specification |
| Product Type | Dichroic Optical Filter / Longpass Beamsplitter |
| Cut On Wavelength | 678nm ± 1 nm |
| Angle of Incidence (AOI) | 45° |
| Reflectance | ≥98% |
| Transmission Range | > 90% average |
| Working Wavelength Rang | 350-900nm |
| Coating Type | Hard-coated dielectric multilayer |
| Substrate Material | Fused Silica |
| Surface Quality | 60/40 or better (per MIL-PRF-13830B) |
| Size Options | 15*11*1.0mm, custom sizes available |
| Clear Aperture | > 90% of dimension |
| Fluorophores | Compatible with Fluorophores Like Cy5.5，Alexa Fluor 680，Alexa Fluor 700 ，APC-Cy7 |
678nm Long Pass Dichroic Mirror Applications
- Deep tissue fluorescence imaging
In living or thick tissue samples, short-wavelength (such as blue light, green light) fluorescence signals are easily scattered by tissue or strongly absorbed by hemoglobin, while red light/near-infrared signals have stronger tissue penetration and lower background interference. For far-red fluorophores such as Cy5.5 and Alexa Fluor 680, the 678nm long-pass dichroic mirror can accurately reflect the excitation light and transmit the emission light to achieve efficient signal capture. Improve image clarity and tissue penetration depth, enhance the visualization of deep targets, - Multicolor fluorescence imaging channel separation
In multicolor imaging, the emission spectra of different fluorophores are prone to overlap, resulting in channel crosstalk, especially between red series such as TRITC and Cy5. The 678nm long-pass dichroic mirror can be used in the spectroscopic system, which only transmits emission signals such as Cy5 and reflects shorter wavelengths (such as TRITC) to ensure the independence of each channel signal. This can reduce channel overlap and misjudgment, and ensure the accuracy and repeatability of multiple fluorescence imaging. - FRET Imaging
In FRET experiments such as GFP-mCherry or CFP-Cy5, it is necessary to accurately distinguish donor excitation light, donor fluorescence and acceptor fluorescence to prevent the energy transfer signal from being submerged by strong excitation light. The 678nm dichroic mirror can reflect excitation light such as 488nm and 561nm, and only transmit FRET acceptor signals >690nm, thereby improving the sensitivity of energy transfer detection. - Far-Red Detection in Flow Cytometry
During multi-parameter flow analysis, there is an excitation or emission overlap problem between near-infrared fluorophores (such as APC-Cy7) and commonly used dyes (such as FITC, PE) channels, which may cause misclassification or submersion of weak positive signals. The 678nm long-pass mirror can reflect excitation light of 640nm, block scattered light and crosstalk in the range of 500–600nm, and only allow far-red emission signals around 780nm to pass through.
