Developmental long trace profiler using optimally aligned mirror based pentaprism
A low-budget surface slope measuring instrument, the Developmental Long Trace Profiler (DLTP), was recently brought into operation at the Advanced Light Source Optical Metrology Laboratory. The instrument is based on a precisely calibrated autocollimator and a movable pentaprism. The capability of the DLTP to achieve sub-microradian surface slope metrology has been verified via cross-comparison measurements with other high-performance slope measuring instruments when measuring the same high-quality test optics. In the present work, a further improvement of the DLTP is achieved by replacing the existing bulk pentaprism with a specially designed mirror based pentaprism. A mirror based pentaprism offers the possibility to eliminate systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of a bulk pentaprism. We provide the details of the mirror based pentaprism design and describe an original experimental procedure for precision mutual alignment of the mirrors. The algorithm of the alignment procedure and its efficiency are verified with rigorous ray tracing simulations. Results of measurements of a spherically curved test mirror and a flat test mirror using the original bulk pentaprism are compared with measurements using the new mirror based pentaprism, demonstrating the improved performance.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Advanced Light Source Division; Engineering Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 1004163
- Report Number(s):
- LBNL-4149E; TRN: US1100611
- Journal Information:
- Optical Engineering, Journal Name: Optical Engineering
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
47 OTHER INSTRUMENTATION
ACCURACY
ADVANCED LIGHT SOURCE
ALGORITHMS
ALIGNMENT
DEFECTS
DESIGN
EFFICIENCY
FABRICATION
MEASURING INSTRUMENTS
MIRRORS
OPTICS
PERFORMANCE
surface metrology
surface profilometer
interferometric microscope
modulation transfer function
power spectral density
calibration
fabrication tolerances
metrology of x-ray optics