A linewidth-narrowed and frequency-stabilized dye laser for application in laser cooling of molecules.

D P Dai,Y F Fang,Y N Yin,Y Xia,X X Yang,X J Li,J P Yin

doi:10.1364/oe.22.028645

Abstract

We demonstrate a robust and versatile solution for locking the continuous-wave dye laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers. The dye laser is first stabilized with respect to a reference cavity by Pound-Drever-Hall (PDH) technique which results in a single frequency with the linewidth 200 kHz and short-term stabilization, by stabilizing the length of the reference cavity to a stabilized helium-neon laser we simultaneously transfer the ± 2 MHz absolute frequency stability of the helium-neon laser to the dye laser with long-term stabilization. This allows the dye laser to be frequency chirped with the maximum 60 GHz scan range while its frequency remains locked. It also offers the advantages of locking at arbitrary dye laser frequencies, having a larger locking capture range and frequency scanning range to be implemented via software. This laser has been developed for the purpose of laser cooling a molecular magnesium fluoride beam.

Highlights

In the past few years, a new approach, laser cooling and trapping of diatomic molecules has become possible [1,2,3,4,5]
The software will analyze these data points and get the negative feedback voltage of the transfer cavity and the reference cavity to lock the localizations of these peaks
From the figure we can find that the voltage of the transfer cavity is changing to compensate the fluctuation of the temperature and the flow of the air, and the voltage is fluctuating in the short term because the ambient temperature and air flow are fluctuating and random

Summary

Introduction

In the past few years, a new approach, laser cooling and trapping of diatomic molecules has become possible [1,2,3,4,5]. The development of a molecular MOT should really mirror the huge historical success achieved by the atomic MOT [6]. Realizing such a powerful technique for producing a diverse set of dense, ultracold diatomic molecular species will open a new chapter for molecular science and it will greatly advance understandings in precision measurement, strongly correlated many-body quantum systems and physical chemistry in the most fundamental way [7,8,9,10]. Due to the large number of diatomic molecules, there are many more candidates as well suitable for laser cooling experiment. The wavelengths for less of candidate molecules are accessible by diode lasers [2,3], most of them need continuous-wave (cw) dye laser or Titanium: Sapphire laser to provide the light source for cooling and trapping experiments [4,5]

Methods

Results

Conclusion