An optical system includes a laser diode, a collimating lens and first and second housing parts. The first housing part retains the collimating lens therein. The second housing part engages the first housing part to retain the laser diode therebetween. The position of the laser diode is adjustable with respect to the collimating lens in X, Y and Z directions. One or more biasing members are interdisposed between the housing parts in the X direction, the Y direction, and/or the Z direction for biasing the laser diode relative to the collimating lens in the X direction, the Y direction and/or the Z direction. One or more securing members fixedly engage the first and second housing to one another and provide a compression force on the housing parts to maintain the relative position of the laser diode with respect to the collimating lens in the X, Y and Z directions.