Can I replace 1 pane of a double pane window. The outside pane is broken, is there anyway to replace just the outside pane
Yes, either the interior or exterior pane can be replaced by a glazer (window company).
Most glazing companies have “on site” services, including replacing panes of glass. They will remove the broken pane, glazing tape, insulation bead, etc. and replace with new...
They will need to remove the unbroken pane too, in order to properly seal the panes together.
However, be careful that the glass matches in color, coating, tint, etc. (especially if adjacent to other windows) before they remove the unbroken pane.
Your glass is insulated or dual glazed. To replace one side of it is harder and virtually impossible than just removing and replacing the whole thing.
To maintain a sealed I.G. Unit you would just need to replace the whole thing, e.g. both sides.