430nm Bandpass Filter

Context: This patent describes a portable instrument for Fluorescence Correlation Spectroscopy (FCS), a technique used to detect single molecules in small volumes (e.g., femtoliters) for biological and chemical analysis.

Usage of Filter: An excitation filter within the illumination module.

Function: The filter is placed in the optical path of the light source (which can be a laser or LED) to selectively transmit a narrow band of light centered at 430nm. This specific wavelength is chosen to match the absorption peak of specific fluorescent labels or dyes used in the sample.

Result: It ensures that the sample is excited only by the specific 430nm wavelength, minimizing background noise and preventing the excitation of other non-target fluorophores. This allows for precise measurement of molecular diffusion times and concentrations.

Context: This patent (related to Dolby 3D technology) details a system for projecting 3D images using spectral separation, where the left and right eyes perceive images formed by different sets of primary color wavelengths.

Usage of Filter: A spectral separation filter (specifically part of the "low blue" passband channel).

Function: The filter creates a multi-band pass structure where one of the blue passbands is designed to transmit light in the 420nm–440nm (centered around 430nm) region for one eye, while blocking the "high blue" wavelengths (e.g., 460nm–480nm) reserved for the other eye.

Result: It effectively separates the left-eye and right-eye images based on wavelength rather than polarization. This achieves a high-contrast 3D effect that is robust against head tilting and can be projected on standard white screens (unlike polarization systems that require silver screens).

Context: This patent describes a solid-state laser system that generates tunable visible light using Optical Parametric Oscillators (OPO) and harmonic generation.

Usage of Filter: An output conditioning filter for specific harmonic generation.

Function: When the system is tuned to generate blue radiation (specifically mentioned as 430nm in the description), the bandpass filter is used to transmit this generated signal wavelength while blocking the residual pump beam (e.g., infrared or 532nm) and idler wavelengths.

Result: It provides a clean, monochromatic 430nm laser output suitable for applications like high-density optical storage, spectroscopy, or medical diagnostics, without interference from the generating laser frequencies.