Scratch & Dig

Scratch & Dig in coated and uncoated elements is an old issue and still very important due to some misunderstanding of the relevant standards (sometimes difficult to understand due to some kind of legal language and too complicated to use) by the users or disagreements with the designations and the explanations by the users, especially with the scratches matters. Standards themselves are important for the common language for the users all over the world and of course in this Website I'm not going to take a stand for any position. But, I will mention the very wide and good explanations of the standards and their meanings for Scratch & Dig issue of two well-known and professional people in this area: David M. Aikens and Matt Young.

David M. Aikens

Dave Aikens is president and founder of Savvy Optics Corp, a Connecticut optics company dedicated to serving the optics industry through practical optical design and engineering, and offering products and training that is required for the 21st century. Before striking out on his own, Dave was in the metrology engineering group at Zygo Corporation, the optical engineering group at Thermawave (now KLA-Tencor), and the NIF optical design and fabrication group at Lawrence Livermore National Laboratory. He has been working on national and international optics standards and specifications for more than 15 years.

Technical Specification – Comparison Standard – Scratch And Dig Samples (Davidson D-668) by Savvy Optics Corporation.
Website: http://www.savvyoptics.com/files/SP4_D-668_technical_sheet.pdf
Software Assisted Scratch Visibility Measurements – The SavvyInspectorTM (May 2009) by David Aikens – Savvy Optics Corp. and Ari Siletz – CCDMetrics.
Website: http://savvyoptics.com/files/Software_Assisted_Scratch_Visibility_Measurement.pdf
Objective Scratch and Dig Measurements (2012) by Dana Takaki and David M. Aikens, Savvy Optics Corp.
Website: http://www.savvyoptics.com/files/Objective_scratch_and_dig_measurements_-_Takaki_20122.pdf
The Truth About Scratch and Dig (2010) by David M. Aikens, Savvy Optics Corp.
Website: http://www.savvyoptics.com/files/Aikens_OFT_2010_Truth_about_scratch_and_dig_rev2.pdf
The scratch and dig revolution (April 2013 Revision 2.0) by Dave Aikens, , Savvy Optics Corporation,
Website: http://www.savvyoptics.com/files/The_scratch_and_dig_revolution3.pdf
Optics Surface Quality Solutions: The scratch and dig revolution (May 2019) by Dave Aikens, Savvy Optics Corporation.
Website: http://www.savvyoptics.com/files/Scratch_and_Dig_Primer_2019.pdf
Scratch and dig numbers by Dave Aikens, Savvy Optics Corporation.
Website: https://www.sizes.com/units/scratch_and_dig.htm
Implementation of ISO 10110 optics drawing standards for the National Ignition Facility (July 1999) by David Yu-Hsi Wang, R. Edward English Jr. and David M. Aikens, Lawrence Livermore Laboratory, Proceedings Volume SPIE 3782, Optical Manufacturing and Testing III.
Website: https://doi.org/10.1117/12.369230
Meaningful surface roughness and quality tolerances by Dave Aikens, Savvy Optics Corporation.
Website: http://www.savvyoptics.com/files/Aikens_IODC_2010_meaningful_roughness_and_quality_manu2.pdf
The Truth About Scratch and Dig (Jan 8, 2020) by David Aikens, Savvy Optics Corporation,
Website: https://blog.rossoptical.com/blog/the-truth-about-scratch-and-dig

Matt Young

Matt Young was Senior Lecturer in the Departments of Physics and Engineering and then Teaching Professor in the Department of Physics at the Colorado School of Mines in Golden, Colorado, from 1999 to 2017. From 1976 until 1999, he was a Physicist with the National Institute of Standards and Technology in Boulder, Colorado, and Chairman of NIST’s Boulder Editorial Review Board.

The scratch standard is only a cosmetic standard by Matt Young, published November 1, 1985. Proceeding Volume SPIE 1164, Surface Characterization and Testing II, (20 December 1989), San Diego, United States.
Website: https://doi.org/10.1117/12.962822
Scratch and dig standard revised by Matt Young, Applied Optics Vol. 25, Issue 12, pp. 1922-1929 (1986), Optical Society of America.
Website: https://www.osapublishing.org/ao/abstract.cfm?uri=ao-25-12-1922
An interview with Matt Young on the scratch and dig standard for optics – Interview of Matt Young BY Robert E. Fischer, Editor of Optical Engineering Reports, No. 44/AUGUST 1987.
Download Link: Click Here
Conference on optical scattering standards by Matt Young, pages 133 and 134, SPIE Vol. 181 Contemporary Optical Systems & Components Specifications (1979). Event: Technical Symposium East, 1979, Washington, D.C., United States.
Website: https://doi.org/10.1117/12.957357
Redefining the Scratch Numbers (NDS Technical Note 1080) by Matt Young and Eric G. Johnson, Jr. Issued February 1985 by U.S. Department of Commerce and National Bureau of Standards.
Website: https://www.govinfo.gov/content/pkg/GOVPUB-C13-0d634e4929d5ad3a44c5049e686d6630/pdf/GOVPUB-C13-0d634e4929d5ad3a44c5049e686d6630.pdf
Tunable Scratch Standards (3 September 1985) by Matt Young, Eric G. Johnson Jr., Richard Goldgraben, Event: 1985 Los Angeles Technical Symposium, 1985, Los Angeles, United States.
Website: https://doi.org/10.1117/12.946347

Scratch & Dig – additional articles/reports

Technical Note: Optical Surfaces by Newport Corporation (part of MKS Instruments, Inc.).
Website: https://www.newport.com/n/optical-surfaces

Technical Note: Optical Filter Surface Quality by Newport Corporation (part of MKS Instruments, Inc.).
Website: https://www.newport.com/n/optical-filter-surface-quality

Scratch and Dig Numbers by Sizes.com.
Website: https://www.sizes.com/units/scratch_and_dig.htm

Scratch-Dig Paper by Sydor Optics.
Download Link: Click Here.

Understanding Surface Quality Specifications by Edmund Optics.
Website: https://www.edmundoptics.com/knowledge-center/application-notes/lasers/understanding-surface-quality-specifications/

The adversarial relationship between optical performance and scratch-dig (9 September 2010), by Cody B. Kreischer, Proceedings Volume SPIE 7652, International Optical Design Conference 2010; 76521K (2010).
Website: https://doi.org/10.1117/12.870033

Scratch & Dig Analysis of Optical Elements by Michael J. Broyles OPTI 521 College of Optical Sciences University of Arizona Fall 2006 Revised 2010.
Download Link: Click Here

Surface Quality Scratch-Dig Definition by Rayotek Scientific, Inc.
Website: https://rayotek.com/PDF/Quality-Scratch-Dig-Definitions.pdf

Samples of scratches, digs and other damages on substrates and coatings (coating failures and handling) by Michael Hausner.
Download Link: Click Here.

Understanding Surface Quality: A Practical Guide by John C. Smith - Rocky Mountain Instruments Co. (RMI). Taken from Photonics Media Website: https://www.photonics.com/Articles/Understanding_Surface_Quality_A_Practical_Guide/a57165

Specifying Scratch/Dig of an Optical Surface MIL-O-13830 by Jason Kuhn 12/12/12. The University of Arizona, Wyant College of Optical Science.

Website: https://wp.optics.arizona.edu/optomech/wp-content/uploads/sites/53/2016/10/ScratchDig_Tutorial.pdf

Presentation: Download Link

A Novel Approach Towards Standardizing Surface Quality Inspection (2016) by Fabian Etzold, Daniel Kiefhaber, Arno F. Warken, Peter Würtz, Jenny Hon and Jean-Michel Asfour, DIOPTIC GmbH, Bergstraße 92 A, 69469 Weinheim, Germany, Darmstadt University of Applied Sciences, Schöfferstr. 3, 64295 Darmstadt. Proc. SPIE Volume 10009, Third European Seminar on Precision Optics Manufacturing, 1000908 (30 JUNE 2016).

Website: https://doi.org/10.1117/12.2235743

Scratches, Digs and other damages on coatings and substrates by Michael Hausner.

Download Link: Click Here

Quality Control – Material/Specification: Scratch & Dig specification by KO Knight Optical (UK) Limited © and Night Optical USA LLC. Can be found through Technical library: Quality Control & Metrology: Quality control Scratch and dig specification QC-SD.

Website: https://www.knightoptical.com/

TFD, Inc., Quality Control by TFD - Thin Film Devices, Inc., taken from TFD, Inc. Catalog,

Website: https://issuu.com/tfdinc/docs/tfd__inc._catalog

Download Link: Click Here

Scratch and Dig Measurement - A Way Ahead by Lionel R Baker.

Proc. SPIE Vol. 0680, Surface Characterization and Testing (23 March1987).

Event: 30th Annual Technical Symposium, 1986, San Diego, United States.

Website: https://doi.org/10.1117/12.939597