Place a rack in the center of your oven and preheat to 400°F. Line a baking sheet with aluminum foil. (You can use non-stick spray if you plan on serving and eating the skin. If you do not use spray, the skin will stick to the pan and the salmon will easily come away from the skin for serving.)
Place the salmon filet skin-side down on the lined baking sheet. Drizzle with olive oil.
Sprinkle the entire salmon with blackened seasoning, gently rubbing the seasoning onto the filet.
Bake for 16-20 minutes, or until the salmon is flaky and cooked through. (For medium, cook to an internal temperature of 130°F.)
Meanwhile, in a large bowl, combine corn, tomato, red onion, jalapeno, cilantro, lime juice, green onion, garlic, and kosher salt. Mix well and place in the refrigerator to chill as the salmon is cooking.
When the salmon is done, top with the corn salsa. If desired, squeeze a lime wedge over the salsa.
Cut the salmon into single-serving portions and serve.