Volume 7, Number 3 May/June Contour Grinding Results on the Nanotech 150AG Jeff Ruckman, Ed Fess and Dennis Van Gee

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1 Volume 7, Number 3 May/June 1999 Contour Grinding Results on the Nanotech 150AG Jeff Ruckman, Ed Fess and Dennis Van Gee Introduction COM-developed deterministic microgrinding (DMG) process technology has been extended to a new computer-controlled contouring microgrinder that can produce highly accurate aspheric optical surfaces in minutes. The new microgrinder, the Nanotech 150AG, was built for COM by Moore Nanotechnology Systems (Keene, NH). It is a CNC controlled, ultra-precision machining system that is capable of generating axisymmetric aspheric optical surfaces up to 100 mm in diameter. The contouring DMG process produces aspheric surfaces within 1 µm of the intended surface shape with significantly lower surface roughness and less subsurface damage than conventional grinding processes. Figure 1: Contour grinding on the Moore Nanotech 150AG. This article reports on a comprehensive study of the contour grinding process for 12 commonly used optical materials that represented a wide range of hardness and fracture toughness. The results demonstrate that the Nanotech 150AG is capable of producing parts to near-finished quality in a range of optical materials. The table below shows the twelve materials included in the study. Figure 2 illustrates the variety of physical properties of the glasses chosen for this study. Table 1: Materials included in grinding study. Optical Glasses Crystalline/Polycrystalline SF 6 SK 19 K 7 CaF 2 ZnS BaSF 2 LaF 2 LF 5 ZnSe Silicon F 7 BK 7 continued on page 2 Inside: Job Postings... 5 COM Summer School... 7 Industry Calendar... 8 Copyright University of Rochester CENTER FOR OPTICS MANUFACTURING 1

2 continued from page 1 Figure 2: Hardness and fracture toughness of glasses included in this study. Methodology For each material, 5 plano parts were contour ground under the same grinding conditions. Each part was measured for figure and finish and checked for surface artifacts, such as chatter or spiral marks. The 40 mm diameter parts were ground on the Nanotech 150AG according to the process described below. Each part was first ground using a rough, 10/20 µm grit, bronze bond tool and then finished with a 2/4 µm resin bond tool using 3 finishing passes (see Table 2). Both tools were spherically dressed before the start of grinding. The cycle time per surface was 4 minutes for rough grinding and 30 minutes total for finish grinding (three grinding passes of 10 minutes each). Table 2: Grinding process. Grind Tool Tool spindle speed (rpm) Rough 10/20 µm bronze bond Fine 2/4 µm resin (607c) bond Work spindle speed (rpm) Feed rate (mm/min) DOC (µm) Final Depth of Cut (DOC) was taken in three passes of 4 µm, 4 µm, and 2 µm. Results The Nanotech 150AG was able to grind optical glasses to a Å rms surface finish and hold figure error to less than 1 µm. The crystalline and polycrystalline materials were ground to approximately 200 Å rms surface finish with figure error also less than 1 µm. Figure error was measured on the Zygo GPI interferometer and surface roughness data was taken on the Zygo New View 100. All values in Table 3 (see page 3) are the average measurements of five parts for each material type. 2 continued on page 3

3 continued from page 2 Table 3: Material properties summary and grinding results (average of five surfaces per material type). Glass type Hardness (kgf/mm 2 ) Fracture toughness (MPa m 1/2 ) Ductility index Figure error (µm) P-V areal roughness (µm) RMS areal roughness (Å) SF BaSF K F SK LaF LF BK ZnS CaF Silicon ZnSe Total average: Total standard deviation: Conclusions These results demonstrate that the Nanotech 150AG is capable of producing precision optical parts to near-finished quality in a wide range of materials. The best result achieved for each material ground is provided in Figure 3 (page 4). Over the entire range of materials, the surfaces achieved were better than 1 average p-v figure error with less than 100 Å rms surface roughness. Acknowledgements COM would like to thank Schott Glass Technologies, Inc., and especially Arnie Bazensky and Bob Chamberlain at Schott, for their help in selecting the glasses used, and for supplying some of the materials. Additionally, COM would like to thank the members of the asphere grinder Manufacturing Advisory Board (Eastman Kodak, Lockheed Martin, Raytheon TI Systems, QED Technologies, Resultant Manufacturing Services) and Moore Nanotechnology Systems for their invaluable technical support, and DARPA for the funding support that made this program possible. For information on the contour grinding program, or other COM activities, please contact Jeff Ruckman or Harvey Pollicove at For information on the Nanotech 150AG, contact Moore Nanotechnology Systems at continued on page 4 We welcome your submissions! Fax or your news and job postings to Michele Richard at COM fax: MRIC_COM@LLE.ROCHESTER.EDU Stop by and visit COM on the web! 3

4 continued from page 3 Deterministic Microgrinding Results Contour Grinding on the Nanotech 150AG Optical Glass Materials SF µm P-V figure 53 Å RMS BaSF µm P-V figure 67 Å RMS K µm P-V figure 39 Å RMS F µm P-V figure 62 Å RMS SK µm P-V figure 45 Å RMS BK µm P-V figure 37 Å RMS LaF µm P-V figure 44 Å RMS LF µm P-V figure 48 Å RMS Crystalline and Polycrystalline Materials ZnS 0.29 µm P-V figure 89 Å RMS CaF µm P-V figure 83 Å RMS Silicon 0.34 µm P-V figure 79 Å RMS ZnSe 0.28 µm P-V figure 99 Å RMS Figure 3: Best results achieved for each material ground. 4 CONVERGENCE May/June 1999

5 JOB POSTINGS Melles Griot Optics 55 Science Parkway Rochester, NY Attn: Deborah Gsellmeier Fax: Title: Marketing Manager Description: Responsibilities include all aspects of marketing for the Rochester Division. Demonstrated ability to effectively sell and market division s product lines is required, as well as excellent communication skills, strong technical writing skills, project management of promotion/development of product, and the ability to understand technical concepts of optical product lines. Experience: BS in Physics, Optics or EE required. Minimum of five years experience in the optics/optical products marketplace. Melles Griot Photonics Components Millikan Avenue Irvine, CA Attn: Sherry Ramirez Fax: Title: Optical Engineer Description: Will support technical/sales inquires, product training, new product development, and trade shows. A thorough understanding of optics, opto-mechanical hardware, instruments, and lasers is required. Experience: BS in Optical Engineering and 3-5 years of photonics industry work experience. The MicroDisplay Corporation 3055 Research Drive San Pablo, CA Attn: Madelyn Homick Fax: mhomick@microdisplay.com Title: Director of Optics and Materials Description: Coordinate OM R&D and manage OM group efforts on projects. Must have high level knowledge of optics and the effects/ interactions of optics with LCD systems. Design application-specific optical systems; develop innovative optical systems that optimize displays and/or customer product; manage work schedules and direction of OM group; order and maintain equipment; attend seminars/ conferences, attend group/project meetings; maintain lab, projects, documentation. Experience: MS/PhD in Optics/Liquid Crystal Technology; 5+ years experience in Optics/LC product development. Experience with stateof-the-art display technology a plus. Title: Liquid Crystal Manufacturing Technologist Description: Guide and assist in the manufacturing of LCDs within MicroDisplay's pilot manufacturing facility. Research existing and future LC material and associated applications/technologies leading to development/manufacture of microdisplays. Improve the performance of existing displays; interface with other design groups. Identify and develop manufacturing process leading to successful assembly of microdisplays; identify and resolve LC material-related display issues; plan/execute approved projects to improve the performance and assembly of microdisplays; assist in benchmarking and testing/ characterization of displays. Experience: Experience with characterization/process of liquid crystal materials in a commercial environment; knowledge of semiconductor and flat panel display equipment. Experience in high volume manufacturing of liquid crystal displays, and/or of electronic components or assemblies, is a must. Title: Senior Research Engineer - Optics Description: Definition of optical specifications for products and demonstration prototypes for microdisplays. Work with product development group in the design and engineering of products and demonstration prototypes; interface with research scientists, marketing, and management to develop MicroDisplay technology into consumer products. Provide optical assistance to other groups on request. Experience: MS/PhD in Physics, with a specialization in optics. 3+ years of experience in research/product development with micro-optics. Mindrum Precision Inc Fourth Street Rancho Cucamonga, CA Attn: Diane Mindrum Fax: Title: Optical Technician Description: To machine and/or polish ring laser gyros. Experience preferred; various positions available. Please fax the number above for more information. PFG Precision Optics 733 Bienville Blvd Ocean Springs, MS Attn: Gayden Gladman Fax: gayden@pfgoptics.com Title: Sales and Marketing Representative Description: Manages marketing strategies, new market development, customer service, and product development. Also responsible for interpreting customer requirements, estimating manufacturing quotations, ordering raw materials, and interfacing with optical technicians and managers. Customer contact primarily via telephone, , and fax. Limited travel. Experience: Must possess excellent communication, organizational and analytical skills. Degree in science or engineering desirable; technical experience in lieu of degree will also be considered. Plummer Precision Optics 601 Montgomery Avenue Pennsburg, PA Attn: Human Resources Department Fax: continued on page 6 5

6 JOB POSTINGS (CONT D) Title: Optical Manufacturing Engineer Description: To be involved in the design, implementation and improvement of processes used to fabricate high precision customer optics. Experience: Qualified candidates should have a BS degree in Optical Engineering or Physics; 2+ years experience in manufacturing is preferred. Experience in the following areas is desirable: optics and optical assembly manufacturing; interferometric and prototype testing; computer aided design; process/procedure documentation. Title: Quality Assurance Manager Description: Develop and document inspection requirements and techniques for raw material, in-process and finished products; recommend/initiate corrective action for in-process defective parts and customer returns; maintain the measuring and test equipment calibration program; examine new orders to determine customer specifications and environmental requirements for the production process. Experience: Qualified applicants should have a BS degree in Optical Engineering with a minimum of 5 years experience in an optics manufacturing and supervisory capacity. Knowledge of government contract specifications (MIL standards) is required. Raytheon Missile Systems Co. TU, Building 840, MS East Hermans Road Tucson, AZ Attn: Frank Degel Fax: fcdegel@mail.hac.com Title: Master Optician Description: Lead activities in Optical Element Fabrication Lab; read/interpret engineering blueprints; develop processes and methodize fabrication of prototype and low volume precision optical components; fabricate optical components (lenses, mirrors, windows, domes, prisms) ranging in size from 0.1 to 8 inches; fabricate components having unique geometries (tilted and off-axis components, unique mounting features, etc.); fabricate optical components from a wide variety of optical materials including glasses, metals, and crystalline IR materials. Applicant will be responsible for leading the day-to-day activities in the lab, for maintaining inventory of consumables, and managing the lab s workload. Experience: Expertise in precision machining (NC equipment and diamond point turning is desirable, but not essential). Speedring Systems, Inc Waterview Drive Rochester Hills, MI Attn: Barb Mobey Fax: barbm@speedringsys.com Title: Senior Diamond Machinist Description: To program and turn aspheric profiles in aluminum, nickel, copper and other optical metals. Must be able to use precision optical measuring equipment; read/interpret complex blueprints; perform setups. Some training of entry-level machine operators. Experience: Minimum 5 years experience as a diamond machinist in the optics industry. Sverdrup Technology, Inc. 620 Discovery Drive Huntsville, AL Attn: Human Resources Fax: Title: Diamond Turning Machinist (Job Code AST007) Description: Diamond turning of metallic optical components for next generation, space-based x-ray telescopes and other optical instruments including LIDAR systems. Experience: 3+ years hands-on experience in the manufacturing of optical elements on large and small diamond turning machines is required. Must be experienced in the fabrication of flat, spherical, and aspheric surfaces, including optical flats, and off-axis parabolic mirrors. Experience in the diamond turning of Fresnel lenses and cylindrical mirror mandrels with hyperbolic and parabolic surfaces for x-ray imaging is desired. Title: Optical Metrologist (Job Code AST006) Description: Support the fabrication of precision space optics by assisting with the measurement of optical surfaces for figure and finish during and after the fabrication process of reflective and transmissive optics. Experience: 5+ years experience with optical interferometry, optical alignment, and precision mechanical measurements is required. Associates degree in electro-optics or physics is desired. Familiarity with WYKO instruments for measuring surface roughness, and ZYGO interferometers for surface figure, is also desired. Title: Video Engineer (Job Code 4035) Description: Provide technical support for the development and application of imaging systems for Microgravity Research. Experience: BS in EE or Physics. Journeyman level engineer. 3+ years working experience in video systems design, including cameras, recording devices and switches. 3+ years experience working with flight systems is desired. Title: Opto-Mechanical Designer (Job Code MH3) Description: Support the development of advanced optical systems for space applications including next generation visible and x-ray telescopes, earth/wind measuring LIDAR systems, and state-of-theart large optics fabrication techniques. Experience: BS in Mechanical Engineering or related discipline and 12+ years experience in the design of mechanical hardware for optical systems and the application of CAD/CAM software (Solid Edge and/or EMS) for design development is required. Experience in the design of tools and fixtures for machining operations is desired. Please send resume to address above and reference job code. 6

7 New Machines, Tools and Processes for Modern Optics Manufacturing (with Labs) COM s annual summer school, New Machines, Tools and Processes for Modern Optics Manufacturing, will be offered from June 21-24, 1999 in Rochester, New York. The course is organized into 21 talks and tutorials providing an overview of emerging technologies that will shape the way optics are manufactured into the next century. Guest speakers join the Center for Optics Manufacturing/University of Rochester professors and engineers to present the most recent manufacturing technology advances in deterministic processing and flexible automation for producing spherical, aspheric, and conformal optics. The program is very interactive, providing two full afternoons of laboratory work on computer integrated manufacturing of aspheres, programming a CNC machine for complex shapes, on-machine probes, magnetorheological finishing, and modern optics metrology. The cost for the 4 day course is $1,000; more information may be obtained by contacting Gayle Thompson at the Institute of Optics (phone , fax , GAYLE@OPTICS.ROCHESTER.EDU). AGENDA Monday, June 21 COM Introduction and Next Generation Optics Issues Chemical Effects in Classical Optics Fabrication Deterministic Microgrinding of Spheres, Aspheres, and Conformal Optics Survey of Commercial Systems for Optics Manufacturing New Polishing Slurries Ion Beam Processing of Optics Tour of COM Open House at Schneider Optical Machinery Tuesday, June 22 What Mechanics and Materials Can Do for Optics Manufacturing How Diamond Tools Work Glass Vibration Analysis of CNC Machines for Optics Manufacturing CNC Generating Lab Materials Science/Classical Optics Fabrication Lab Open House at OptiPro Systems Wednesday, June 23 Magnetorheological Finishing (MRF) Optical Polishing Pitch Chemical Mechanical Polishing in Semiconductor Manufacturing Modern Optics Metrology Lab Magnetorheological Finishing Lab Open House at QED Technologies Thursday, June 24 Interferometric Form Metrology for Precision Machined Surfaces Dwell Maps and Tool Paths for Deterministic Sub-aperture Polishing Design and Manufacture of Precision Polymer Optics Efficient Glass Grinding Coolants and Bound Abrasive Polishers Single Point Diamond Turning John Schaefer (Raytheon) Harvey Pollicove (UR/COM) Michael Cumbo (OCLI) Jeff Ruckman (UR/COM) Arne Lindquist (Schneider) David Rostoker Dale Zajac (Eastman Kodak Company) John Lambropoulos (UR/ME) Paul Funkenbusch (UR/ME) Sheryl Gracewski (UR/ME) Don Golini (QED Technologies) Birgit Gillman (Zygo Corp.) Eric Funkenbusch (3M) Andrew Kulawiec (Tropel Corp.) Greg Forbes (Macquarie University) Michael Missig (Opkor, Inc.) Birgit Gillman (Zygo Corp.) 7

8 1999 Industry Events Representatives from COM will be attending the following optics industry events. Stop and see us at: NEWSLETTER MAILING LIST UPDATE Please let us know of any address corrections, additions, or deletions by completing this form. Mail or fax to Michele Richard at the Center, fax COM Summer School 99, Rochester, NY June 21-24, 1999 SPIE Annual Meeting 99, Denver, CO July 18-23, 1999 Photonics East 99, Boston, MA September 20-22, 1999 OSA Annual Meeting 99, Santa Clara, CA September 26 - October 1, 1999 Name: Title: Company: Address: City, State, Zip: Phone: Fax: 8 CENTER FOR OPTICS MANUFACTURING University of Rochester 240 East River Road Rochester, NY CONVERGENCE May/June 1999