Rocky Mountain Instrument Co.

Complex Optical Assemblies

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If you need specialized optical engineering support, RMI is uniquely qualified to assist you. Our end-to-end opto-mech program incorporates state-of-the-art design services, vertically integrated manufacturing capabilities (including an in-house machine shop), and advanced testing and metrology.

As a small company with large enterprise capabilities, we take pride in collaborating closely with our clients to deliver ideal opto-mechanical solutions quickly and affordably. Because we offer so many years of experience in prototyping and manufacturing, you can rest assured that you will receive leading-edge technology, unmatched engineering support and careful attention to your precise needs.

Our complete in-house optical assembly program includes advanced capabilities in optics, coatings, diamond turning, machining, assembly and certification. We specialize in creating customized lens objectives, prism assemblies, optical transmitter and receiver assemblies, and advanced optical fixtures.

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Custom Optical Products

  • Laser Optics Assemblies
  • Prism Assemblies
  • Lens Assemblies & Lens Objectives
  • Optical Transmitter & Receiver Assemblies
  • F-Theta Lenses
  • Beam Expanders 

Design & Engineering


We create all of our opto-mechanical designs using Zemax and SolidWorks software. We offer unrivaled expertise in optical construction, mechanical housing, complex (multi-element) assemblies and custom test setups. Our dedicated optical engineers specialize in the following product categories:

lens-assembly-design-screen opto-mech-design-screen

Lens Objectives

Wavefront Irregularity Tolerance
Commercial Standard High Precision
3 Wave 1 Wave 1 Fringe

Prism Assemblies

Wedge Tolerance
Commercial Standard High Precision
<3 arcmin <1 arcmin <20 arcsec

Optical Transmitter / Receiver Assemblies

Source Types Sensor Types
Fiber Laser Germanium
LED Silicon
Incandescent GaAs
Diode Laser CCD Camera

Advanced Optical Fixtures

Designs for advanced optical fixtures may implement full translational and rotational adjustbility for zoom lenses, tip/tilt mounts, etc. RMI's optical engineers make careful considerations for performance and application of the assembly, and have extensive experience with various surface finishes including nickel plating and anodizing.


 Clean Room 2  Manufacturing-Testing

Our complete in-house optical assembly process includes full document control as well as a focus on the most timely service and delivery. Our opto-mech manufacturing capabilities include:

Bonding Methods

UV-Curable Epoxy-Heat Cured Mix / Dry
Norland 61 Mil-Bond Adhesive B/C Grey
Loctite 3311   3M RTV Silcone

Blocking / Tooling Methods

RMI has developed a unique solution to combine prisms for enhanced transmission that preserves tight tolerances throughout the entire assembly process.

Alignment Tolerance:
Bonding Method
Alignment Tolerance:
Blocking Method
<30 arcsec <30 arcsec

In-House Machine Shop

• Faster Tooling & Prototyping
• Supports Custom Test Beds
• Experience with Wide Range of Metals & Plastics

Clean Room Assembly

• Class 1000 / 100 Clean Room Capability
• Mobile Clean Room Setup with Advanced Tests 

 Metrology & Optical Alignment

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RMI's complete in-house testing and metrology program incorporates the most advanced technologies with expert opto-mechanical engineering support. Our wide range of testing capabilities include:

Beam Deviation Testing

• Assures accurate photon delivery based on mechanical constraints 
• Unique processes available for various assembly types

Deviation Test Type Measurement Range
Floating Pass Through 30 sec – 5 min
Custom Die Mounts Pass Through 10 sec – 1 min
Mechanical Flange Perpendicularity 30 sec – 5 min
Angle-Block Calibration Auto-Collimation 0.5 sec – 2 min

Beam Location Testing

• Allows for quick and accurate alignment of mechanical and optical axis 
• Using high resolution Basler camera, we can locate beam position in “x” and “y” plane to micron-level precision

Beam CG (Center of Gravity) / Location Tolerance
Commercial Standard Precision  
0.5 mm 0.25 mm  20 micron  

Centration Testing

• Verifies optical alignment of lens vertices
• Developed unique procedure to align air gapped optical assemblies using overlaying interferograms

Zygo / Transmitted Wavefront Testing

• Verifies several optical properties of OM assemblies:

— Flange Focal Length
— Transmitted Wavefront Irregularity 
— Advanced Prism alignment

Mach Zender Interferometry

• Used as alignment tool for complex multi-element assemblies 
• Compatible with wide range of 11 in-house laser sources

Beam Quality / Collimation Testing

Test Type Used For Collimation Tolerance
Sheer Plate Small Aperture <1 arcmin
Beam Dimensioning Large Aperture <15 arcsec

Power Distribution Testing

• Gives a rough estimate of the aberrations present in the output wave front of the system 
• PSF (Point Spread Function) based test qualifies wave front coherence

MTF / Image Quality Testing

• Modular transfer function to quantify image quality (contrast) 
• Modified testing setup using optical rail and custom mount blocks to streamline testing
MTF Setup Parameters Specification
Magnification Range 2 – 200x
Line Pairing (7th Group-Smallest) 100/mm2