1. Mix first three liquid ingredients and pour into a nine- by 13-inch pan. Add salmon fillet, skin-side up, and marinate, covered, for two to four hours in refrigerator. Bring to room temperature before cooking.
2. Peel oranges and remove orange segments from membranes. Discard membranes and place oranges into bowl; set aside.
3. Mix next seven ingredients in medium bowl and fold in orange segments with any juices.
4. Preheat oven to 450 degrees Fahrenheit. Line rimmed baking sheet with foil and generously brush with oil. Place fish, skin-side down, on baking sheet. Sprinkle with salt and pepper. Bake until just opaque in center, about 20 to 25 minutes.
5. Using large spatula and foil as an aid, carefully lift and slide salmon onto serving dish. Mound relish down center of fish, sprinkle with sesame seeds, and serve.