Laser Asphere Frequently Asked Questions


LaCroix Precision Optics was recently featured in the 2018 Fabrication Daily News magazine. The following is the excerpt from the magazine. 


LaCroix Precision Optics: Laser Asphere Frequently Asked Questions

Kenny Rains is a Technical Sales & Manufacturing Engineer for LaCroix Precision Optics. Rains has been with LaCroix for 3 years. Rains holds a Bachelor of Science degree in Electrical Engineering and Masters of Engineering Management.

Q: Why is an asphere better than a spherical lens at focusing laser energy?

A: Aspheres can drastically reduce the spot size of a laser beam as compared to a spherical lens, which increases the density of the laser power. For applications such as laser cutting, this reduced spot size and increased density of laser power can lead to a cleaner and quicker cut.

Q: What types of Fused Silica do you offer and how do I know which one is right for my application?

A: We offer a wide variety of Fused Silica from Corning, Hereaus, Nikon, Tosoh, and more. As far as knowing which one to use, the largest factors would be the transmittance of the material at the specified wavelength, OH content, homogeneity, inclusions, metallic impurities, thermal properties, price, and lead time. We have several datasheets available on our website to find out more information about various types of Fused Silica and you can always reach out to us or the fused silica manufacturer.

Q: What are some reasonable specifications for an asphere?

A: We get this question a lot, in fact we are making an entire blog series about this specific question. For the aspheric side, form error and slope error are important to specify. A standard form error would be 0.5um peak to valley and 0.25um/mm with a 1mm integration window for slope error. We can definitely hold tighter dependent on the geometry and material of the asphere. Just reach out to us, we are happy to advise. Check out our optical manufacturing tolerance chart, which includes our top 10 tips for aspheric design from a manufacturing perspective in addition to a table with suggested specifications. Don’t forget about surface quality either!

Q: What kind of lead times do you offer on custom laser optics?

A: This can be answered with a big depends. The largest driver of lead times would be material availability. We have some material in house and can quickly source Corning 7980 fused silica to offer lead times anywhere from 4-6 weeks for prototypes to 8-10 weeks for larger volumes. Some types of fused silica may have lead times from 8 weeks to 3 months. Be sure to ask about material availability when designing your optics and when requesting a quote.

Q: How can our readers find out more about your company?

A: For more information, call (870)-698-1881 or visit


About LaCroix Precision Optics

For over 71 years, LaCroix Precision Optics has positioned itself as one of the premier domestic volume and prototype manufacturers of custom precision optics. Capabilities include spherical, aspherical, plano and custom-coated optics. At the facility in Batesville, Arkansas, both traditional and advanced CNC processing methods are used to achieve the highest level of precision and quality demanded by customers. LaCroix Precision Optics is certified to ISO 9001:2015, and is ITAR certified and compliant.