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 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. https://safeersappliancers.shop/product-category/faber-victory-2-0-x-a99-99cm-stainless-steel-built-in-cooker-hood-extractor/