In 1928, Indian scientist Raman discovered the Raman effect for the first time in a light scattering experiment using a mercury lamp irradiating liquid benzene.

Limited by the mercury lamp as a monochromatic light source, the Raman scattering effect is very weak, and the research field is limited to the vibration spectrum of chemical molecules. It was not until 1960 that the American physicist Maiman invented the ruby laser, which gradually replaced the mercury lamp as a monochromatic light source. The field of Raman spectroscopy research expanded to include solids, liquids, gases and other forms of matter. However, the intensity of laser is many orders of magnitude higher than that of Raman scattered light. In order to effectively separate the laser from Raman scattered light, it is necessary to suppress the laser through a double or even triple monochromator. The overall structure of the system is bulky.

In 1990, Puppels et al. first proposed to use a set of parallel Raman notch filters to replace part of the cascade monochromator, reducing the laser intensity by 108~109W/mm², and the detected Raman signal intensity was enhanced to 4 times. Positive and negative Stokes detection can be achieved simultaneously. This not only improves the detection accuracy of the instrument, but also simplifies the overall structure.

With the sharp increase in market demand for detection technology that is non-destructive, real-time, fast, rich in information, and high in analysis efficiency, Raman detection technology has developed rapidly and is widely used in fields such as biomedicine, chemical analysis, environmental monitoring, criminal investigation, and archaeological research. Has been widely used.

At the same time, in order to effectively suppress stray light in the detection system, output high-quality Raman signals, and improve the detection accuracy of the instrument, optical thin film devices are also more diverse and functional. We have developed and produced products that can meet the needs of different Raman detection instruments. Interference filters (referred to as "Raman filters") required by application scenarios.

At present, representative foreign manufacturers include Semrock, Chroma, Iridian, etc.

Recently, Omeda has developed Raman filters with high transmittance, high aperture and cut-off depth.

Fig1:532nm Long Pass band Optical Filter

Fig2：785nm Long Pass band Optical Filter

We have advanced  coating machine and testing equipment all over the world.We regard optical coating  ”advanced science“，and we know how to fabricate and test to meet client's demands.

If you want to know more about our hardware about production and testing, please click this link:

Coating Machine and Testing Instruments for Optical filter 

Optical Products Inventory List

Omeda have rich experience in biomedical products,we do many projects with our clients and accumulated a lot of stock filter, the stock filters list can help you save a lot of money on sample cost.

Biomedical Filter Inventory.xlsx

Remark：In addition to common wavelengths, we warmly welcome you to customize specified wavelength, half-width, transmittance, and cut-off depth filter ; we are especially good at dual-wavelength and multi-wavelength bandpass filter .

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About Hennan Omeda Technologies Co.,Ltd

Omeda is a company that focuses on the production of advanced optical and semiconductor components. Our team consists of several PhDs who study optical components and semiconductor component processing. We have extensive experience in glass molding technology,glass polishing technology, through-silicon via and through-glass via technology, optical coating technology, optical fiber device technology, lithography technology,Nanoimprint technology, free-form surface, metasurface and diffractive optical design.

Our business involved in Lidar,consumer electronics,Biomedical,3D Sensing, AR,VR,fiber communication,Laser Projection and Display,high power laser and so on. We provide advanced optical and semicondutor components for clients to make their design become real products.

Email:omedaoptics@gmail.com

Tel/Whatsapp:+86 151 1838 3837