Mr. Shreeyam Kacker Profile

Shreeyam Kacker

at MIT Star Lab

SPIE Involvement:

Author

Publications (3)

SPIE Journal Paper | 27 November 2023

Optical performance of commercial liquid lens assemblies in microgravity

Shreeyam Kacker, Kerri L. Cahoy

OE, Vol. 62, Issue 11, 113106, (November 2023) https://doi.org/10.1117/12.10.1117/1.OE.62.11.113106

KEYWORDS: Liquid lenses, Lenses, Liquids, Wavefront errors, Optical engineering, Reflection, Monochromatic aberrations, Collimators, Beam diameter, Point spread functions

Read Abstract +

Proceedings Article | 26 August 2022 Presentation + Paper

Laser-guided space interferometer

Leonid Pogorelyuk, Paul Serra, Shreeyam Kacker, Sophia Vlahakis, Nicholas Belsten, Gioia Rau, Kenneth Carpenter, Laurent Pueyo, John Monnier, Ewan Douglas, Kerri Cahoy

Proceedings Volume 12183, 121831E (2022) https://doi.org/10.1117/12.2630605

KEYWORDS: Stars, Mirrors, Interferometers, Signal to noise ratio, Diffraction, Laser guide stars, Space mirrors, Sensors

Read Abstract +

Proceedings Article | 5 March 2021 Presentation + Paper

Link analysis for a liquid lens beam steering system, the miniature optical steered antenna for intersatellite communication: MOSAIC

Shreeyam Kacker, Ondrej Cierny, Jared Boyer, Kerri Cahoy

Proceedings Volume 11678, 116780T (2021) https://doi.org/10.1117/12.2582607

KEYWORDS: Telecommunications, Liquid lenses, Beam steering, Optical communications, Liquids, Antennas, Radio optics, Mirrors, Zemax, Transmitters

Read Abstract +

Laser communications can enable more efficient and higher bandwidth communications across longer distances than conventional radio frequency (RF) systems. However, beam divergence angles for laser systems are narrower than typical RF systems, and require precise pointing, acquisition, and tracking systems to establish and maintain the link. In addition, typical lasercom links are point-to-point, and not capable of multicast or broadcast. Conventional pointing and tracking (PAT) systems use mechanical gimbals or fast-steering mirrors. Mechanical gimbals may not meet the size, weight, and power (SWaP) constraints for small spacecraft, particularly for multiple concurrent spatially diverse beams. Fast-steering mirrors while compact and efficient have limited aperture size, and many would be needed to provide multiple links over a hemisphere. The Miniature Optical Steered Antenna for Intersatellite Communications (MOSAIC) aims to provide nonmechanical pointing and tracking using liquid lenses, allowing a wide field-of-view and support for multiple concurrent links. Initial work with commercially available liquid lenses showed that liquid lenses can be used in a space environment and assessed spatial coverage. In this work, we model a transmitter using three liquid lenses. One on-axis lens provides focusing capability. Two off-axis and perpendicular lenses provide beam steering, with a fisheye lens amplifying the effect. This provides near-hemispherical pointing up to 170 degrees. We investigate beam quality and divergence using a Zemax model and conduct a link analysis dependent on the beam steering angle and rotation angle. A 25 Mbps link with 200 mW transmit power at 1550 nm (optical C band) and 16-ary pulse position modulation (16-PPM) can be maintained up to 28 km separation with 3 dB margin for an Optotune EL-16-40-TC liquid lens. Losses are primarily due to the liquid lenses limiting aperture size to 16 mm. We also consider the impact of diffusers for increasing numerical aperture through a simple ray transfer analysis and experimental results.

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years