| 摘要 |
A laser diode supplemented with a filter (9) between a laser crystal (5) and a monitor diode (7), so that the monitor diode (7) can be used as a detector for light, incident upon the laser diode, of another wavelength than that emitted by the laser crystal (5). The filter (9) has the property that it reflects or absorbs that light which the laser crystal (5) present in the laser diode emits inwards towards the monitor diode (7) and transmits light of other wavelengths. As detector for the received light the existing monitor diode (7) is utilized or, if space is provided within the laser diode package, a photodiode intended for that purpose. The built-in filter (9) is mounted separately between the detecting monitor diode (7) and the laser crystal (5) or is applied as a thin filter substrate directly on the surface of either this detecting monitor diode (7) or the laser crystal (5). A modified laser diode according to the invention is used as the only active component during simultaneous transmission and reception of signals in connection with an optical fibre. |
