document: A simple etalon-stabilized visible laser diode Visible laser diodes -LRB- LDs -RRB- are inexpensively available with single-transverse-mode , single-longitudinal-mode operation with a coherence length in the metre range . With constant current bias and constant operating temperature , the optical output power and operating wavelength are stable . A simple and inexpensive way is developed to maintain a constant LD temperature as the temperature of the local environment varies , by monitoring the initially changing wavelength with an external etalon and using this information to apply a heating correction to the monitor photodiode commonly integral to the LD package . The fractional wavelength stability achieved is limited by the solid etalon to 7 * 10/sup -6 / degrees C/sup -1 /
doc_bio_tags: O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O O B I I O O O O O O O O O O O O O O O O O
extractive_keyphrases: visible laser diode constant current bias constant operating temperature heating correction monitor photodiode fractional wavelength stability
abstractive_keyphrases: etalon-stabilized laser diode single-transverse-mode single-longitudinal-mode index-guided multi-quantum-well closed-loop operation feedback loop