Iridian offers a range of customized Raman filter and spectroscopic filter solutions for both portable handheld devices and bench top Raman instruments. We can customize filter design to meet customer requirements as well as optimize existing designs to fit specific applications or spectral detection parameters set by the Raman instrument user. Our custom Raman edge filter solutions boast exceptionally high transmittance levels and blocking over a wavelength range between 340 nm and 2000 nm. Precise use of filters gives Raman spectroscopy fantastic utility not only in material analysis and drug identification but also the detection of explosives and unknown substances, and food safety inspection.

Band-pass Filters

Iridian bandpass filters are ideal for use in applications such as fluorescence based, flow cytometry, Raman spectroscopy, LIDAR, and spectral imaging. Single-band, multiband, wideband, and narrowband filters are available.

Depending on the wavelength ranges and requirements of your system, our bandpass filters can be custom designed to meet one or more of the following challenging specifications:

• Greater than 90% transmission for passbands in the visible range and NIR range 2000 nm
• Up to OD6 wide range out of band blocking
• Edge transitions as steep as 0.5% of CWL from 50% T to OD6
• Typical FWHM 0.5-2.2 nm

A typical 532nmm BPF is illustrated below.

We also offer multiple band-pass filters. These filters can have 2, 3, or even 4 band regions to allow use of multiple excitation sources or emission bands.

Notch Filters

A combination of high transmittance (>90%) in the pass band and deep blocking (OD>6) outside the pass band are offered with notch width 20-70 nm FWHM depending on the wavelength.

A typical 785nm notch filter is illustrated below.

Edge Pass Filters

Iridian offers both short and long pass edge filters with industry leading cut-off values 25-100 cm -1 from OD6 at the laser wavelength to the 50% transmission point. The US LPF has cut-off 40-50 cm-1 range and the Nano LPF has cut-off between 25-30 cm-1.

• Greater than 90% transmission for passbands in the visible range up to 1700-2000 nm
• High blocking > OD6 and extended wavelength blocking from 350 nm to the laser wavelength
• Edge transitions as steep as 0.5% of CWL from 50% T to OD6
• Low ripple < 4% on the pass band

A typical 532nm LPF filter is illustrated below.

Dichroic Filters

Iridian offers both long pass and short pass dichroic edge filters with high transmission at the transmitted bands and high reflection at the reflection bands. A dichroic filter is typically used at an angle of incidence of 45° to reflect (transmit) excitation light to the sample and transmit (reflect) the emitted signal to the detector. The wide angle edge filter series offer superior performance for wider angle of incidence (AOI 0-2 °) and cone half angle (CHA 5 °) applications.

A typical 532nm dichroic is illustrated below.

Please provide your custom filter specifications and contact our sales team to discuss your filter requirements.