Sharp nose lens design using refractive index gradient
Abstract
For infrared sensors located at the nose of a missile or a
projectile, an age-old problem occurs. A conflict between
optical quality and aerodynamic drag exists. A new approach
for solving this problem is being developed using gradient
refractive index, GRIN, for lens design. The equations for
lens design incorporating GRIN are formulated for the special
case of spherically symmetrical GRIN. A computer code for designing a GRIN lens and for determining aberrations has
been developed. A different program (LENS) calculates
lens design and lens performance for the case of homogeneous
refractive index. Results of this program provide a check
on the more complex program which includes GRIN. The
computed program calculates the spot diagram for both meridianal
and skew rays. The spot diagram, which is the intersection
of rays with the focal plane, is plotted, and the Oj-j^g
and centroid location of the spot diagram are calculated.
Also a cumulative energy diagram is obtained from the program.
The computer code has been organized to calculate the items
enumerated above for either a circular cone for the inside or
outside surface of the pointed lens. For homogeneous
refractive index, both cases are included in the program
discussed in this report. However, for the GRIN case, only
the complete program for a lens with a conical surface on
the outside is reported here. The alternate case is being
developed by a thesis student.
Features of the computer program include the following: use
of many subroutines for clarity and for easy modification, and
use of program structure for easy integration into an
optimization code.
Sample lens designs and lens performance are presented. The
computer code provides the tools for lens design. Considerables
additional work is needed for selecting the best lens design.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.NPS Report Number
NPS67-82-003CRRelated items
Showing items related by title, author, creator and subject.
-
A computer graphics approach to non-linear circuit design.
Tynan, John Malcolm Calhoun (Monterey, California. U.S. Naval Postgraduate School, 1967-06);This Investigation is concerned with computer and programming requirements for on-line network design. A class of problem involving non-linear diode resistance networks was chosen. Such networks provide a useful form ... -
Steady state response of a second order servo-mechanism with backlash and resilience in the gears between motor and load
Anderson, Norris O.; Luckett, Thomas W. (Monterey, California: U.S. Naval Postgraduate School, 1961);This thesis is concerned with the steady state response to a step input of a non-linear s ervomechani sm having viscous friction and a load position unity feedback loop. A gear train with "backlash between resilient gear ... -
Calculations for axial compressor blading with uniform inlet enthalpy and radial enthalpy gradient
Schlachter, W (Monterey, California. Naval Postgraduate School, 1981-05); NPS67-81-008A computer program was used to calculate the radial distribution of flow parameters in an axial compressor stage designed to have a symmetrical velocity diagram at the mean radius and particular variations of reaction from ...