title: Passive intrinsic-linewidth narrowing of ultraviolet extended-cavity diode laser by weak optical feedback.
abstract: We present a simple method for narrowing the intrinsic Lorentzian linewidth of a commercial ultraviolet grating extended-cavity diode laser (TOPTICA DL Pro) using weak optical feedback from a long external cavity. We achieve a suppression in frequency noise spectral density of 20 dB measured at frequencies around 1 MHz, corresponding to the narrowing of the intrinsic Lorentzian linewidth from 200 kHz to 2 kHz. Provided additional active low-frequency noise suppression and long-term drift compensation, the system is suitable for experiments requiring a tunable ultraviolet laser with narrow linewidth and low high-frequency noise, such as precision spectroscopy, optical clocks, and quantum information science experiments.
authors.forename: Polnop
authors.initials: P
authors.lastname: Samutpraphoot
authors.forename: Sophie
authors.initials: S
authors.lastname: Weber
authors.forename: Qian
authors.initials: Q
authors.lastname: Lin
authors.forename: Dorian
authors.initials: D
authors.lastname: Gangloff
authors.forename: Alexei
authors.initials: A
authors.lastname: Bylinskii
authors.forename: Boris
authors.initials: B
authors.lastname: Braverman
authors.forename: Akio
authors.initials: A
authors.lastname: Kawasaki
authors.forename: Christoph
authors.initials: C
authors.lastname: Raab
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Kaenders
authors.forename: Vladan
authors.initials: V
authors.lastname: Vuletić