In this paper, a widely tunable external cavity diode laser (ECDL) with an ultra-high side mode suppression ratio (SMSR) was fabricated.Three configurations were Machine Accessories constructed to investigate the relationship between the grating features and the SMSR.When a 1200 grooves/mm grating with a first order diffraction efficiency of 91% is utilized in the external-cavity laser system, a maximum SMSR of 65 dB can be achieved.In addition, the tunable range reaches 209.
9 nm.The results show Visor Cap that the laser performance can be improved by proper high grating groove number and first-order diffraction efficiency.