(CUI) GWEF MWIR Relay Lenses Technical Requirements 20250403 (U)_Redacted.pdf

CUI//SP-CTI

iii

Abbreviations, Acronyms, and Symbols g Force per unit mass due to gravity at the Earth's surface GWEF Guided Weapon Evaluation Facility IR Infrared mm Millimeters

MWIR Midwave Infrared µm Micrometers

” Inch (Inches) iv

Table of Contents

Abbreviations, Acronyms, and Symbols ....................................................................................... iii Table of Contents ........................................................................................................................... iv

1. Introduction

2. Physical Requirements

3. Environmental Requirements

4. Optical Performance Requirements

1. Introduction

a. This technical requirements document is for two midwave infrared (MWIR) relay lens assemblies lens assemblies to be used at the Guided Weapon Evaluation Facility (GWEF), . The two custom optical assemblies will be used to develop a GWEF test system and must be drop-in replacements to an existing GWEF test system.

b. Contractor proposals should identify any specifications that are not technically feasible or have an undue impact on cost. Should this occur, proposals should provide recommended alternatives to the identified specification as well as impacts on overall system performance and cost.

2. Physical Requirements

a. The physical volume shall not exceed the following volume:

i. MWIR relay lens assembly length: 236.67 mm (9.31”)

ii. MWIR relay lens assembly width & height: (165.10 mm) 6.5” height

b. Each lens assembly shall include aluminum dust covers on both ends. In addition, the vendor shall engrave on the cover fiducial marking to assist with alignment and proper clocking.

c. The vendor shall engrave the relay lens type, vendor name and part number on the front and on the body of the assembly visible with the dust covers on both ends.

d. Mechanical assembly color: flat black.

3. Environmental Requirements

a. Operating temperature and humidity range: 65 to 75 degrees Fahrenheit and 20% to 50% humidity, non-condensing. The performance requirement in this document shall be met over this operating range.

b. Storage temperature and humidity range: 40 to 95 degrees Fahrenheit and 5% to 95% humidity, non-condensing. The lens assembly shall be capable to be stored in an area with this range with no degradation of performance.

c. Operating shock and vibration range: 3 to 10 g environment. The performance requirement in this document shall be met over this operating range.

4. Optical Performance Requirements

a. The MWIR relay lens optical requirements are given in Table 1 below. The requirements below marked with an asterisk are defined for a system comprised of the assemble and an existing 16.8” diameter OAP (16” clear aperture), 44.9” vertex focal length, 13.5” zonal radius. The combined system shall work as a collimator with an un-obscured pupil.

Table 1. MWIR Relay Lens Requirements

MWIR Relay Lens Optical Requirements Spectral Range 1.9-5.5 µm Transmission (assessed via witness sample reflectivity)

>70%, 1.9-2.5 µm >80%, 3-5 µm

Encircled Energy* 84% (within 46 µm diameter circle) Relative Illumination* (at the flat focal plane)

≥94% of cos4θ, where θ is any off axis angle within the square 8 degree FOV

Exit Pupil Size at SUT* ≥76 mm (2.99”) Exit Pupil Offset* 2377.83 mm (93.62”) form SUT aperture to OAP section vertex Entrance Pupil Diameter* 24.576 mm Entrance Pupil Offset* (from end of mechanical housing)

109.36 mm (4.31”)

Effective Focal Length* 176.3 mm Front Working Distance 848.17 mm (33.39”) Back Working Distance 109.36 mm (4.31”) Total FOV Presented to SUT* 8-degree circular

Grid Distortion* <3% across the field of view Vignetting* No vignetting within the exit pupil diameter Ghost images and narcissus* Optimized to minimize using best engineering practices

Scratch/Dig 60-40 Anti-Reflective Coating All optical elements will have anti-reflective coatings to preclude ghosting and optimize transmission