LED based lamps are disclosed. In an embodiment, an LED based lamp includes a concave optical diffuser, a concave neodymium-doped glass bulb, a reflector, a printed circuit board that includes a plurality of light-emitting diodes (LEDs) configured to emit light, and a heat sink body. The concave optical diffuser has a first interior volume, and the concave neodymium-doped glass bulb is positioned within the first interior volume. The neodymium-doped glass bulb defines a second interior volume, and both the reflector and the printed circuit board are positioned within the second interior volume. The reflector includes a sloped annular wall with an inner reflective surface and an outer reflective surface, and a bottom portion of the reflector is connected to the printed circuit board. The heat sink is thermally connected to the printed circuit board and to the reflector.