Wind Lidar Working Group, 29 June 2005 Welches, OR

The SHADOE Takes Form: Progress in UV and 2-micron HOEs

Geary Schwemmer

Meeting of the Working Group on Space-based Lidar Winds

Welches, Oregon

June 28- July 1, 2005

Work supported by:IPO & NASA

Wind Lidar Working Group, 29 June 2005 Welches, OR

Topics

• HOEs & SHADOEs

• Holographic wavefront error correction

• SHADOE optical design

• Space qualifications

• 2-micron HOEs

Wind Lidar Working Group, 29 June 2005 Welches, OR

HOEs & SHADOES

Rotating Holographic Optical Element (HOE)

Shared Aperture Diffractive Optical Element (SHADOE)

Wind Lidar Working Group, 29 June 2005 Welches, OR

Holographic Wavefront Correction for SHADOE LIDAR

Receivers

Wasatch Photonics SBIR• Phase 1

– 355 nm– Wavefront correction to < 50 µrad FOV – 30° in / 30° out– 90% efficiency (per optic, 80% system)– afocal and focusing designs– 5-6 FOVs– 40 cm primary

• Phase 2– 355, 1064 & 2054 nm– 40° in / 30° out– diffraction limited spots (2054 nm only)– 50 – 100 cm primary

Wind Lidar Working Group, 29 June 2005 Welches, OR

150°

Baseline Scan Configuration

Satellite nadir ground track

YA= 324 km

YB= 87 km

30°

Z = 400 km, = 40°

YC= 237 km 90°324 km

237 km

3 tracks, 6 lines of sight

0 90

seconds timing

12 7833 57

Wind Lidar Working Group, 29 June 2005 Welches, OR

Optical Layout(single HOE)

Wind Lidar Working Group, 29 June 2005 Welches, OR

Six-HOE SHADOE Design

Wind Lidar Working Group, 29 June 2005 Welches, OR

Conical Truss Frame

Wind Lidar Working Group, 29 June 2005 Welches, OR

SHADOE Focal Spots, 2 power levels

mm units

inch units

Wind Lidar Working Group, 29 June 2005 Welches, OR

Solar UV exposure effects

Wind Lidar Working Group, 29 June 2005 Welches, OR

2-Micron grating test

40-45% diff.eff.

Normal Incidence Transmission

Wind Lidar Working Group, 29 June 2005 Welches, OR

Summary

• HOEs & SHADOEs

• Holographic wavefront error correction under development

• SHADOE optical-mechanical design

• Space qualifications

• 2-micron HOEs

Wind Lidar Working Group, 29 June 2005 Welches, OR

Hybrid SHADOE Roadmap

TRL5TRL4

TRL3

45deg.

HOE: 400mm dia.,52.5mm dia. centered hole,45deg bore angle

Fold Mirror 1:45 AOI, 2” dia.

30mm dia. Laser

Option 2

~4”

C/L

Fold Mirror 2:22.5 AOI, 2” dia.

Side View

Wind Lidar Working Group, 29 June 2005 Welches, OR

HOE Optical Properties

  Working Copy

Master

Spot Size at 86% of Total Energy

250 µm 215 µm

Focal Length 993 mm 995 mm

Diffraction Efficiency

~62 % ~40 %

Diffraction Angle 45o26’ 44o81’

Wind Lidar Working Group, 29 June 2005 Welches, OR

Wavefront Error Correction

Wave-front corrective

prescription applied to cover glass

Wave-front distortion caused by HOE materials

Wind Lidar Working Group, 29 June 2005 Welches, OR

Hybrid Concentric SHADOE Receiver

(One FOV shown)

IR

Wave-front corrective

lenses near focal plane

Wind Lidar Working Group, 29 June 2005 Welches, OR

Hybrid R-T Combination SHADOE Receiver(One FOV shown)

UV Reflection SHADOE

IR Transmission SHADOE

IR Focal Plane

UV Focal Plane

Wind Lidar Working Group, 29 June 2005 Welches, OR

UV HOE Doppler Demo