FC-HX Series Microscopic Phase Contrast Ring

Product Description

• Realize phase contrast microscopy;
• Used in combination with phase contrast objectives to enhance image contrast by utilizing the phase difference of light;
• Suitable for phase contrast imaging through bright-field illumination; applicable to observations in cytology, molecular biology and materials science;
• Various phase contrast ring options available;

In a phase contrast microscope, the phase contrast ring is one of the core components for realizing phase contrast microscopy. It is usually used in combination with phase contrast lenses to generate and measure the phase difference between the object and the background.

Specification	Ø25.4*1.7mm
Ring Plate Thickness	0.2mm
Material	Aluminum Alloy + Stainless Steel
Weight	1.9g

 

Microscopic Phase Contrast Ring	Microscopic Phase Contrast Ring	Microscopic Phase Contrast Ring
Model	Ring Specification	Quantity
FC-HX3.1	Ø3.3mm, Ring 0.21*2.44mm	3 pcs
FC-HX3.9	Ø4.8mm, Ring 0.3*3.17mm
FC-HX6.5	Ø7mm, Ring 0.5*5.5mm
FC-HX12	Ø12.7mm, Ring 0.7*10.35mm

Technical Description

– Principle of Phase Contrast Microscopy

When imaging translucent samples under bright-field transmission illumination, the contrast between the sample and the background is very small because it depends on the absorption of light. Phase contrast microscopy improves image contrast by converting phase differences into amplitude differences in the image plane.

– Optical Path Diagram of Phase Contrast Microscope

The key components of a phase contrast microscope are the annular diaphragm and the phase plate. The annular diaphragm is located in the front focal plane of the condenser, limiting the angle through which light waves can pass. The phase plate is located in the back focal plane of the objective lens. Used in conjunction with the phase contrast ring, its material can dim the light passing through the phase plate by an amplitude of 1/4λ. Phase contrast observation uses the principle of light interference to convert this optical path phase difference into amplitude (brightness) changes, thereby enhancing the contrast of the interface and allowing the human eye to distinguish it.

The phase contrast ring forms a hollow light cone from the light passing through the condenser, focusing on the sample (yellow light); after passing through the sample plane, the scattered light (orange) is delayed by -¼λ (typical value). When the direct light—mainly background light—passes through the phase ring, it is shifted by +¼λ and dimmed by 50% (red). These phase shifts cause constructive and destructive interference between the background light and the scattered light in the image plane.

For positive phase contrast, the high-refractive-index phase plate in the objective lens is engraved with a metal-coated phase ring, which can reduce the light transmittance by 50% and shift the light passing through the phase ring by +¼λ. When used with a matching condenser annular diaphragm, the light passing through the phase ring is mainly direct background light, while the light passing through other parts of the phase plate is light scattered by the sample. The interaction of light with the sample produces a typical phase shift of -¼λ. A 180° phase difference (typical value) between the direct light and the scattered light causes constructive and destructive interference in the image plane. The background light is reduced by 50%, making the light intensity difference between the background light and the scattered light obvious, thereby improving contrast. Compared with bright-field images, phase contrast images have greater contrast, are related to phase, and have lower background light signals. Since these objectives use positive phase contrast, the resulting images are relatively dark with a bright background.

When imaging translucent samples under bright-field illumination, the image contrast ΔI only represents the absorption of light by the sample. In phase contrast imaging, the phase plate converts the phase difference generated by sample scattering into amplitude differences through constructive and destructive interference, thereby enhancing the contrast between the background and the sample.

☑ Product Description

(1) In a phase contrast microscope, the phase contrast ring is one of the core components for realizing phase contrast microscopy. It is usually used in combination with phase contrast lenses to generate and measure the phase difference between the object and the background. It is used to improve the contrast of transparent or translucent samples, especially when these samples are almost invisible under a conventional bright-field microscope. It enhances image contrast by utilizing the phase difference of light, and is particularly suitable for observations in cytology, molecular biology and materials science.

(2) Can be installed in a turret phase contrast device, or integrated into a cage system for use with optical turrets, adjustment mounts, and lens sleeves.

(3) The pinhole can also be selected according to actual needs in terms of aperture size and outer diameter to meet different experimental purposes of users.

Assembly

Application Examples

Engineering Drawing

FC-HX Engineering Drawing