A multi-laser transmitter optical subassembly may include N number of lasers, where each laser is configured to generate an optical signal with a unique wavelength. The transmitter optical subassembly may further include a focusing lens and a filter assembly. The filter assembly may combine the optical signals into a combined signal that is received by the focusing lens. The filter assembly may include N−1 number of filters. Each of the filters may pass at least one of the optical signals and reflect at least one of the optical signals. The filters may be low pass filters, high pass filters, or a combination thereof.