Anywhere Light Goes™ Blog
A blog about optical design, build, test and more.
A Review of Optical, Non-Contact Fluid Measurements for Life Science Applications
Optikos has engaged in multiple projects related to non-contact measurement of liquids. Typically, these measurements serve as a quality control (QC) step for an automated fluid handling process. Example projects include: Characterize turbidity (cloudiness) of bacterial samples to evaluate growth rates and populations prior to antibiotic testingPerform a critical, non-contact QC inspection of MRI contrast agents in a flow cell immediately prior to patient injectionPerform QC check of concentration gradients in a centrifuge tube A variety of optical techniques are available depending on the sample characteristics and the required measurement sensitivity. A major challenge for most non-contact measurements is the influence of the sample holder (test tube, cuvette, flow cell, etc.), particularly when the sample holder is of low optical...
Coverslip tolerances are an important aspect of your life science imaging system tolerancing budget
Custom high NA scanning objective made by Optikos Corporation. High-performance microscope objectives are critical to many life science imaging applications including DNA sequencing, spatial biology, super resolution microscopy, oncology diagnostics, and many other imaging modalities. The microscope objective is usually just one component in a complex imaging system used to achieve high-resolution imaging. Designing these imaging systems often requires a holistic and complex systems engineering development process and may include sensors, optical filters, motion stages, illumination optics, microscope objectives, and other mechanical/optical components. However one of the most important and often overlooked components of microscope systems is the coverslip. In microscopic imaging, a coverglass or coverslip secures the specimen or object under investigation. A coverslip also introduces aberrations into the...
Why We Test Lenses Over Temperature: Model Validation, Focus Hysteresis, and Other Unusual Failure Modes
Many applications require high quality imaging over a wide temperature range. This may be due to an uncontrolled environment (e.g. outdoor security cameras), or the intended environment may be regulated to something other than room temperature (e.g. body temperature for endoscopes). However with temperature variation comes thermal expansion, which introduces an opportunity for the flange focal length (FFL) of a lens to change. This shift defocuses the lens from the sensor plane, resulting in a blurry image. If the optomechanics are not designed to minimize this effect in use cases like those mentioned above, the drop in resolution (MTF) of the imaging system can be dramatic. In egregious cases, total mechanical failure (cracking) of lenses has been known to occur....
Parking Lot Parallax
Parallax is something nearly every human, and every animal with a set of forward facing eyes, utilizes every day and they may not realize it. Parallax is the shift in position of objects in a scene when there is a change in the position of the viewer (usually a camera or one of your eyes). Our brains use the parallax in the images from our eyes to create a sense of depth in our vision (stereopsis). In the image at the beginning of the post we see an example of parallax at play. In one image the tree is centered in the image. As the photographer shifts their position, but is still centered on the tree the author can be...
Compensation Methods for Glass Tolerances
Precision optical imaging systems span a wide variety of markets and applications including semiconductor, life science, medical device, aerospace, defense, and other industries. Often these imaging systems necessitate demanding performance requirements including diffraction-limited wavefront image quality, pixel or sub-pixel image distortion, as well as broad-band chromatic aberration correction. In order for the optical system to be manufactured to these requirements, the design often requires various advanced compensation methods during the build process including the use of melt compensation. One technique for melt compensation prescribes element-to-element airspace values for each serial number assembly. This is a multi-step design process. First, measured index of refraction values from glass manufacturers are fit using glass dispersion formulae and interpolated at the design wavelengths of...
