Custom Long Pass Filters

What are long pass filters?

Longpass filters, also known as LP filters, are impoertant optical components that block shorter wavelengths and allow longer wavelengths to pass through.

They can provide precise wavelength separation. Therefore, people often choose them in  laser systems and infrared detection.

Chenyu long pass filter is a cost-effective filter that has an initial wavelength within the range of 400 to 950 nm.

These long pass filters can provide a transmission rate of ≥90% within the transmission band that extends up to 1600 nm.

• Cut-on wavelength (λc): Defines the transition point from blocking to transmission.

• Blocking range: Below λc, typically OD3–OD6 (optical density).

• Transmission range: Above λc, transmission is usually ≥90%.

Key Features of Long pass Filters

• High transmission efficiency in the passband region.

• Steep spectral edge for precise wavelength separation.

• Wide spectral coverage from UV to near-infrared.

• Durable coating designs for high laser damage thresholds.

• Angle tuning capability in certain interference filters.

Applications of Long pass Filters

• Fluorescence Imaging

The filter can block excitation light while transmitting fluorescence emission signals. Also, it improves image contrast and detection sensitivity.

• Laser Systems

The filter provides wavelength selection in optical instruments. It can select the wavelength range according to the customer’s requirements.

• Spectroscopy and Analytical Instruments

The long pass filter is always used in optical measurement and sensing devices.

• Infrared Detection and Thermal Imaging

It can enhance the accuracy of IR cameras and detectors.

• Machine Vision and Industrial Inspection

Improve imaging performance by blocking ambient light.

It is recommended to use a long  pass filter and a short pass filter in combination to obtain specific wavelength usage and create custom band-pass filters.
Chengyu employs advanced production techniques and is capable of customizing the generation of filters. If you have any needs, please contact us.