Place salmon pieces in a large plastic bag, pour 1/2 cup Lime Ponzu over the salmon. Zip the bag securely closed and marinate in the refrigerator for at least 2 hours or overnight. Pour Panko breadcrumbs in a bowl. Dredge marinated salmon in breadcrumbs, coating all sides thoroughly. Place in a non-stick oven pan. Bake at 350°F for 30 minutes. Serve with additional Ponzu.