Photothermal self-phase-modulation technique for absorption measurements on high-reflective coatings

J. Steinlechner, L. Jensen, C. Kruger, N. Lastzka, S. Steinlechner, R. Schnabel*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Web of Science)


We propose and demonstrate a new measurement technique for the optical absorption of high-reflection coatings. Our technique is based on photothermal self-phase modulation and exploits the deformation of cavity Airy peaks that occurs due to coating absorption of intracavity light. The mirror whose coating is under investigation needs to be the input mirror of a high-finesse cavity. Our example measurements were performed on a high-reflection SiO2-Ta2O5 coating in a three-mirror ring-cavity setup at a wavelength of 1064nm. The optical absorption of the coating was determined to be alpha = (23.9 +/- 2.0) . 10(-6) per coating. Our result is in excellent agreement with an independently performed laser calorimetry measurement that gave a value of alpha = (24.4 +/- 3.2) . 10(-6) per coating. Since the self-phase modulation in our coating-absorption measurement affects mainly the propagation through the cavity input mirror, our measurement result is practically uninfluenced by the optical absorption of the other cavity mirrors. (C) 2012 Optical Society of America
Original languageEnglish
Pages (from-to)1156-1161
Number of pages6
JournalApplied Optics
Issue number8
Publication statusPublished - 10 Mar 2012
Externally publishedYes



Cite this