UVFused Silica

Besides its excellent performance in the ultraviolet and visible light bands, fused silica glass also has significant advantages in the terahertz band. Quartz crystals, especially Z-cut quartz crystals, exhibit over 70% transmission in the terahertz band with wavelengths greater than 50μm. This performance makes them suitable for producing terahertz lenses, quartz prisms, and terahertz windows. In the visible range and terahertz band, Z-cut quartz crystals maintain high transmission rates without altering the light's polarization state, providing significant convenience for the adjustment and application of optical systems.

Visible light is composed of lights of various wavelengths. Gathering up all of these lights to a point is ideal for objective lenses.With a single lens, because light is bent in the same way as with a prism, the focal lengths of lights with different wavelengths vary. As a result, not all light rays reach the same point, which causes chromatic aberration.An achromatic lens made with conventional glass materials can match focal lengths of two different wavelengths. For red and blue colors, for example, that contain both ends of the wavelengths of visible light, chromatic aberration can be reduced to a certain extent by conforming their focal lengths. However, with more detailed examination, because light with other wavelengths such as green has different focal lengths, residual chromatic aberration results. This residual chromatic aberration is known as secondary spectrum.Combinations of conventional glasses cannot solve this secondary spectrum problem, but particular optical materials which have a unique characteristic of dispersion are needed.ED (Extra-low Dispersion) glass has this unique characteristic and when combined with other glasses minimizes the effects of the secondary spectrum. Comparing to achromatic lenses, ED glass reduces chromatic aberration to a remarkable degree.

Fused silica transmissionspectrum

Fused silica glass, with its excellent transmission rates and stable optical performance in multiple spectral bands, has become an indispensable material in modern optical systems.

Quartz UVtransmission

A bundle of light rays coming from one point on the optical axis is focused at a different place than the focused point depending on the distance from the optical axis when the light incidents. This deviation is caused by variations in angles of each incident light ray, and is called spherical aberration.Suppose a screen is placed at P' in the illustration above, the image of P will not be a focused point, but a blurred circle. Making the lens diameter smaller reduces such spherical aberration.

Fused silica glass, as a high-quality optical material, is widely used in the manufacture of optical lenses for ultraviolet, visible, and near-infrared light. Its excellent transmission and optical properties make it an ideal choice for manufacturing micro-lens arrays, diffractive optical elements (DOE), lenses, and other optical components. This article will explore the transmission rate of fused silica glass and its transmission spectrum characteristics.

This is caused by a difference in light wavelength. The focal point or magnification of a lens varies according to the wavelength of each type of incident light. Therefore, if you look at an image through a lens with chromatic aberration, color fringing may occur.Because a single lens cannot compensate for chromatic aberration, two lenses of different optical characteristics are combined to correct this aberration.Nikon's original ED (Extra-low-Dispersion) glass lenses effectively compensate for color fringing.

This is caused by the difference in distance of the incident light from the optical axis. While spherical aberration is caused by a difference in focused point, coma is caused by a difference in magnification. A point image such as a star tails toward the exterior like a comet, which "coma" refers to. Coma strongly influences image quality in the periphery of the field.

Quartztransmissionspectrum

Compared to natural quartz, the transmission spectrum of fused silica glass in the range of 270nm to 2600nm has lower transmission rates, especially in the ultraviolet band, where the transmission performance is significantly inferior to Fused Silica Glass. Fused silica glass offers a wider transmission range and higher transmission rates, making it a more ideal choice of optical material.

Fused Silicagrades

IRFused Silica

In the case of a lens fully compensated for coma aberration and astigmatism, the light rays coming from a point apart from the optical axis are focused at one point. But this point is not always included in the vertical plane to the optical axis. This is called Curvature of Field. With a lens having this aberration, even if you focus around the center of the field, the periphery of the field appears out of focus. It can cause very bad effects especially on wide-field-type binoculars.

Fused silicarefractive index

Nikon's binoculars have received high evaluation because of their excellent optical system. Nikon knows that a bright image and sharp details are the priority of binoculars, and makes utmost efforts to achieve this. Correcting lens aberration is vitally important.Nikon's binoculars are designed to correct the aberration described below properly to realize the brightest and sharpest image.

The meridional plane (which contains the optical axis of the lens) and the sagittal plane (which is vertical to the meridional plane) have different radii. Therefore, the meridional and sagittal rays have different focal points. This is called an astigmatism aberration. When a latticepatterned object is viewed using a lens with an astigmatism, horizontal stripes appear in focus and vertical stripes appear out of focus. Conversely, when horizontal stripes appear out of focus, vertical stripes are in focus. Since astigmatism increases in proportion to the incident angle squared, astigmatism greatly influences image quality at the peripheral area of binoculars with a wide field of view.

These categories indicate that fused silica glass has high transmission rates in various spectral regions, demonstrating excellent transmission performance in the far-ultraviolet band (185-2500nm) and the near-infrared band (260-3500nm). For instance, some fused silica glass models can maintain over 80% transmission in the deep ultraviolet band at 165nm, and while absorption peaks may occur around 2800nm, the transmission rate remains above 80% at 3500nm.

Fused silica glass displays excellent optical performance in different spectral bands. Compared to natural quartz, fused silica glass has a higher transmission rate in multiple bands. This material can provide excellent transmission performance in the ultraviolet, visible, near-infrared, and infrared bands, making it widely used in optical applications.

Distortion is caused by variations in the magnification of the image depending on the distance from the optical axis. There are two types of distortion: positive and negative.This image distortion, irrespective of image visibility, increases in proportion to the incident angle cubed.

Fused silica glass's transmission spectrum demonstrates its optical performance in different bands. The transmission spectrum chart indicates that from 250nm to 2800nm, fused silica glass has very high transmission rates. The primary loss is due to reflection rather than absorption. The spectrum's curve exhibits the performance of fused silica glass in different bands while accounting for Fresnel reflection loss (1-R)².