Combine rice vinegar, orange juice, soy sauce and ginger slice in a small saucepan. Reduce over medium heat until a thick glaze forms, about 15 minutes. Turn off heat and whisk in butter until melted and sauce is thickened. Set aside.
Add the sliced cucumber, bell pepper, carrots and apples in a medium sized bowl. Combine and set aside.
For the salad dressing whisk together rice vinegar, orange juice, honey, minced ginger, olive oil and sesame oil until combined. Taste and season with salt and pepper as needed. Add half of the dressing into the cucumber salad mixture, toss to combine and allow to marinate. Reserve the other half of the dressing. Set salad aside or refrigerate if not eating within half an hour.
Preheat oven to 400°F. Cover a sheet pan with foil and lightly grease with oil. Add salmon portions to the pan. Generously season with salt and pepper. Bake for 10 to 12 minutes, until tender and flaky. Drizzle some sauce on top of each fillet. Garnish with sesame seeds.
Serve citrus glazed salmon with cucumber salad on the side, and rice if desired. Drizzle some additional dressing on top of the salad.