Current tuned slotted Y‐branch laser for wafer thickness measurements with THz radiation. Issue 24 (12th September 2021)

• Record Type: Journal Article
• Authors: Surkamp, N.; Gerling, A.; O'Gorman, J.; Honsberg, M.; Schmidtmann, S.; Nandi, U.; Preu, S.; Sacher, J.; Brenner, C.; Hofmann, M. R.
• Is Part Of: Electronics letters. Volume 57:Issue 24(2021)
• Page Start: 936
• Page End: 938
• Publication Date: 2021-09-12
• Subjects: Spatial variables measurement -- Lasing action in semiconductors -- Design of specific laser systems -- Laser beam modulation, pulsing and switching; mode locking and tuning -- Metrological applications of lasers -- Microwave photonics -- Semiconductor lasers -- Laser beam modulation, pulsing and switching; mode locking and tuning -- Metrological applications of lasers -- Spatial variables measurement; Electronics -- Periodicals; 621.381
• DOI: 10.1049/ell2.12314
• Languages: English
• ISSNs: 0013-5194

Abstract

Abstract: A slotted Y‐branch laser diode that emits two spectral modes at a difference frequency of about 1 THz is investigated in the context of photonic based cw‐THz measurements. The beating frequency of the emitted laser light can be tuned by ±10.5 GHz around 1 THz by changing the applied laser current, which allows for potentially fast measurements. A second spectral window of ±6.5 GHz was found at 850 GHz. Pointwise scanning of the difference frequency is demonstrated with thickness determination of HRFZ‐Si wafer samples as a possible application scenario.