As a critical component in optical devices, a glass reticle needs to be precisely manufactured for optimal performance. This week, we’re discussing how these components provide measurements, industry applications, and benefits of glass reticles.
The Role of A Glass Reticle In Optical Devices
The role of the glass reticle spans different industries but is generally used for one of three things—aiming, targeting, or measuring. Although the patterns of the fine lines built into these optical device eyepieces vary by use case, they need to be as precise as possible to achieve optimal accuracy.
For weapon sights or non-weapon measuring instruments, the sets of patterns used provide visual measurement and calibration that impact the instrument’s functionality. In addition to the importance of the material used (in this case, glass) and patterns etched, where the reticle is installed also matters. The focal plane is where these reticles are typically installed within a telescope or scope. Some scopes consist of the first focal plane (FFP) or second focal plane (SFP), which changes the reticle functionality.
However, to fully understand the role of a glass reticle in optical devices, we’ll need to break them down by type.
Reticles are necessary for the functionality of weapon sights or scopes. In many cases, wire reticles made of platinum or tungsten (historically made from spider silk) are still used in rifle scopes. However, glass reticles achieve greater accuracy and measurement. The etchings, usually made by precision photolithography, are often more accurate, allow for multiple crosshair variations, are practically indestructible, and can be applied to complex scopes.
For both systems, the placement and lens security (with bonding through lock rings, glues, and screws) impact the overall accuracy of the reticle. Knowing this and the importance of precise etching, Photo Solutions provides custom reticles up to 2um resolution for scopes.
The crosshair variations made with glass reticles in rifle scopes also apply in telescopes. These include patterns such as fine and duplex crosshairs, German reticle, target dot, circle, old and modern rangefinding, and SVD-type that vary by application. In general, these eyepieces are a critical part of the telescope’s overall functionality, so we know that precision is a must.
Despite differences in telescope patterns, a glass reticle placed in a telescope helps with precise measurements in determining angular distance between stars. Depending on the size of your telescope and the field of view, we can scale up and down the imaged patterns for dedicated purposes.
Reticles in microscopes function similarly to their rifle scope and telescope counterparts. The glass inserts generally sit at the focal planes and have specific patterns imaged for accurate measurement. In this case, the object to measure would be a specimen, so reticles need to function properly at very small scales.
Whether your needs include stereo or binocular microscopes, we can accurately manufacture a reticle that meets your specifications. In addition, we know the necessity of confirming the exact values of reticle markings, so we can provide custom components up to 2um in resolution.
Other Industry Applications
We often think it’s helpful to look at advancements in the industry when referring to our specific components. Often, clients come to our team with specifications like these featured below, and we work with them to produce components that can offer unmatched precision. These industry applications are examples of real-world use-case for reticles.
Laser Sensor Rifle
For military and police, rifle scopes are an oft-used tool for which precision is necessary. A new fiber optic laser-based sensor system could improve sights by automatically correcting for “barrell disruptions.” To do this, the system measures the barrel to the sight and then electronically moves the reticle. Once out of the prototype phase, this advancement could mean more precise scopes that adjust for real-time conditions (like distance).
For deep space observation, advancements in telescopes are critically important. Spectroscopy allows for 3D mapping of gravitational lenses, or “cosmic magnifying glasses.” The lenses can potentially allow for viewing millions of light years away and identifying dark matter. In general, the researchers show that the more magnifying glasses used, the more distant and precise the space surveillance can be.
The Semiconductor High-NA Actinic Reticle Review Project (SHARP) is a collaborative one between Lawrence Berkeley National Laboratory and semiconductor manufacturers. The project is researching an extreme-ultraviolet (EUV) photomask-imaging microscope that will make measurements more precise than ever. Once produced, the new microscope will be ideal for experiments due to special features like illumination coherence control and multilayer coatings for high reflectivity.
Benefits of A Glass Reticle
Although we can create reticle reticles on Mylar and aluminum depending on customer needs, there are some key benefits of using glass for reticles. In general, soda-lime glass is an ideal material for projects that require a high degree of precision. The material is durable and strong, so we can etch precise markings onto the surface without worrying about damaging it.
The type of glass we use is made from high-quality silica sands that make the material transparent and nearly tint-free. This structure is imperative when it comes to integrations into weapon and non-weapon scopes. And because the different applications are often in harsh environments, durability is key. Soda-lime glass is a six to seven on Mohs hardness scale and is highly resistant to abrasion. Lastly, a glass reticle can transmit light with a refractive index of 1.5, which aids in the instrument’s overall precision and accuracy.
Our Other Custom Products
In addition to glass reticle engineering, we also provide custom photonic components for calibration targets and medical devices. For each, we use customer-supplied drawings to create CAD data to image the custom artwork on glass, Mylar, or aluminum substrates. Although we primarily work with these custom projects, we’re always looking for new application requests to meet your engineering needs.
Calibration targets allow for optimal accuracy across various applications in robotics, aerospace, manufacturing, and medical equipment. We manufacture a defined shape grid pattern on the surface of our components that’s specific to the industry and application. We use photolithography down to a 2um resolution to create precise edge features. Additionally, we can machine substrate to customer specifications on glass, quartz, and borosilicate.
Photo Solutions has a long history of supplying ophthalmology components for eye examination instruments, but we can create custom components for different medical disciplines. Our team can create precision grooves, ridges, channels, holes, windows, and other geometric patterns depending on the medical device. Combined with microlithographic patterning, we offer a variety of techniques and solutions to construct microfluidic devices on quartz, soda lime, and borosilicate glass.
For Your Glass Reticle Needs and More
Whether you need a glass reticle for a scope or an encoder disc for a robotic surgery tool, the team at Photo Solutions can meet your engineering needs with our precision photonics manufacturing. Get in touch for a free quote on your next project!