To make salsa, first whisk lime juice and honey in medium sized bowl. Add mango, cucumber, onion, and jalapeno, and stir until well blended. Seal container and refrigerate for at least 1 hour before serving, to allow the flavors to mix. Season with salt to taste.
To prepare salmon, mix cumin, 1/2 tsp salt, and pinch of cayenne pepper in a small bowl.
Lightly coat both sides of the salmon in olive oil (spray or with brush).
Sprinkle spice mixture on both sides of Salmon.
Heat a small non-stick skillet over medium-high heat. Cook the salmon fillets until the outsides are lightly browned (1-2 minutes per side, depending on thickness). Then lower heat and cook until the fillets are pale-pink throughout (2-3 minutes per side).
Season with salt, pepper, cayenne, to taste. Transfer fillets to a plate, and top each with 2 Tbsp of salsa mixture.