AR
CN
DEN
EN
FR
GER
ITA
POR
RUS
SPA
Stress-free objective lenses are designed to eliminate stress in manufacturing and assembly. They are also designed to account for thermal expansion and other environment-dependent changes. This enables them to provide precise, reliable imaging in changing environments.
With applications in medical diagnostics, light microscopy, scientific research, and industrial testing, these objectives prevent distortion by eliminating internal stress. By doing so, they ensure high quality imaging when less advanced lenses might fail.
Stress-free objectives enable advanced polarized light microscopy to perform reliably.
Advanced polarized light microscopy is one field that has come to rely on stress-free objectives. When ordinary objectives are used stress-induced distortions, introduced during lens assembly and curing, can make it impossible to accurately detect the crystallographic air of crystal samples.
Stress birefringence obscures the image, and loss of focus may occur. That’s where stress-free objectives come in. The imaging stability and accuracy necessary for advanced polarized light microscopy is made possible with these carefully engineered lenses.
But what exactly is a stress-free objective lens? These objectives are designed to eliminate any internal stress that might be generated during manufacturing and assembly. Potential sources of internal stress might be:
Designers of a stress-free objective lens use precision assembly equipment and improved bonding processes, along with careful material selection, to create an objective that is not distorted or warped by external forces and stresses.
What sets these objectives apart is their imaging stability and accuracy; accuracy that remains stable even under changing conditions. Let’s take a closer look at the manufacturing process involved.
There’s nothing simple about making stress-free objectives. Unstressed, birefringent materials that have similar mechanical properties are selected, along with high-quality, stress-free adhesives. Analytic modeling is used to design an optical system that will perform without stress-induced deformation, and optical modeling ensures the system will perform as desired. Strict control over the manufacturing process is accomplished with precise measuring tools and automated metrology equipment, and annealing is used to eliminate internal stress.
Assembly is important too. For instance, the holder to which the lens is fixed is designed in such a way that any extrusion stress it might experience won’t be transmitted to the lens. Both the lens pressure ring and pressure cap are tightened only gently, then fixed in place with low-stress glue.
This image shows one possible configuration for stress-free assembly of an objective lens
After assembly, a stress-free lens will be subject to careful quality control to ensure it is, in fact, stress free, and that it will perform as expected in real-world scenarios. Shanghai Optics has a rigorous testing progress that ensures every optic that leaves our factories meets every standard, and when we test stress-free optics we take special care to ensure that no stress will be introduced during normal working conditions.
Standard optics are subject to a wide range of stresses, from those introduced in the manufacturing process to others introduced through daily use. Extreme environments can induce stress, but many deformations are induced under normal use in ideal environments. Accurate imaging requires avoiding these stresses, and this requires the use of specially designed objectives.
Stress-free objective lenses are in demand whenever high precision is required. This is especially important in systems that make use of polarized light— think interferometers, polarimeters, and laser systems— as polarized light is very sensitive to stress birefringence. We use polarized light in scientific research, medicine, and industry, and stress-free objectives make it possible to achieve diffraction-limited imaging.
Science—When highly precise, accurate observation data is required, stress-free objectives may be needed.
Medicine—In medical practice, these lenses can give more clarity, leading to better diagnoses and treatment.
Industry— Stress-free lenses are used for precision inspection routines, enabling personnel to accurately examine crucial details.
At Shanghai Optics, we pride ourselves on our track record of providing high quality stress-free objective lenses and other special optical parts to clients from many fields. Contact us today for a quote or to get more information about our manufacturing capabilities.