Laminar versus trapezoidal grating profiles: AFM measurements and efficiency simulations

Gerd Reichardt; Franz Schaefers

doi:10.1117/12.279367

3 November 1997 Laminar versus trapezoidal grating profiles: AFM measurements and efficiency simulations

Gerd Reichardt, Franz Schaefers

Proceedings Volume 3150, Gratings and Grating Monochromators for Synchrotron Radiation; (1997) https://doi.org/10.1117/12.279367
Event: Optical Science, Engineering and Instrumentation '97, 1997, San Diego, CA, United States

Abstract

Laminar groove profiles promise a high suppression factor for the even orders of reflection gratings. For normal incidence mounts the theoretical suppression of the second order should be nearly perfect if the groove to land ratio of 1 : 1 is matched. Experimental experience with laminar gratings demonstrates that the suppression of the second order is not as good as expected from calculations. Once we understood that the behaviour of the second order contribution cannot be explained in terms of a mismatch of the groove to land ratio alone, we started to investigate the characteristics of laminar groove profiles in more detail by means of atomic force microscopy. The main discrepancy between the idealised laminar profile and the measured profiles is the limited aspect angle of the edges of the grooves: the profiles are rather trapezoidal than laminar. Simulating the diffraction efficiency of the measured trapezoidal profiles revealed that the shallow aspect angle has a significant influence on the higher order diffraction efficiencies. Optimising groove profile parameters under assumption of a realistic aspect angle yielded essentially different values than the same procedure for idealised laminar profiles.

Citation Download Citation

Gerd Reichardt and Franz Schaefers "Laminar versus trapezoidal grating profiles: AFM measurements and efficiency simulations", Proc. SPIE 3150, Gratings and Grating Monochromators for Synchrotron Radiation, (3 November 1997); https://doi.org/10.1117/12.279367

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available