Laser diode assembly and device for operating a laser diode
View Patent ↗The invention is directed to a laser diode assembly having a laser diode and a support, whereon the laser diode is arranged or formed in one single piece. The laser diode assembly further includes a coupling capacitor integral therewith, wherein the laser diode is subjected to the action of a laser driver circuit via the coupling capacitor associated with the assembly. The invention is also directed to a device for operating a laser diode, wherein the device includes a coupling capacitor integral with a laser diode assembly. The invention enables a reduction in the number of coupling paths between a laser driver circuit and a laser diode assembly, thereby reducing the occurrence of parasitic elements.
1. A laser diode unit, comprising:
at least one laser diode,
an integrated circuit with a surface, on top of which the laser diode is arranged or formed monolithically,
connection contacts associated with the laser diode, and
at least one coupling capacitance integrated into the integrated circuit,
the coupling capacitance comprising a first metallization formed at the surface of the integrated circuit and a second metallization formed within the integrated circuit, the second metallization being connected to a contact at the surface of the integrated circuit, and
a signal of a laser driver circuit being applied to the laser diode via the coupling capacitance, wherein the laser driver circuit has a first surface formed at the surface of the integrated circuit and a second surface formed within the integrated circuit.
2. The laser diode unit as claimed in claim 1 , wherein the laser diode is placed by a connection onto the first metallization formed at the surface of the integrated circuit.
3. The laser diode unit as claimed in claim 2 , wherein another connection of the laser diode is realized by a bonding wire.
4. The laser diode unit as claimed in claim 1 , wherein the laser diode unit comprises a single-ended driving configuration, wherein the coupling capacitance comprises a coupling capacitor coupled to the laser diode.
5. The laser diode unit as claimed in claim 1 , wherein the laser diode unit comprises a differential driving configuration, wherein the coupling capacitance comprises two coupling capacitors coupled to the laser diode.
6. The laser diode unit as claimed in claim 1 , wherein the laser diode unit comprises a plurality of laser diodes integrated into a laser diode array which, together with a carrier, the connection contacts and the at least one coupling capacitance, forms the laser diode unit.
7. A laser diode assembly, comprising:
a semiconductor body containing a laser driver circuit configured to provide a bias current and a modulation current, wherein the laser driver circuit has a first surface formed at a surface of the semiconductor body and a second surface formed within the semiconductor body;
a laser diode formed or arranged entirely on the surface of the semiconductor body in a monolithic manner, the laser diode comprising first and second connection contacts associated therewith;
a coupling capacitance formed within the semiconductor body and defining first and second surfaces, wherein the first surface is coplanar with the surface of the semiconductor body and the second surface resides within the semiconductor body, the coupling capacitance further comprising first and second metallizations associated with the first and second surfaces, respectively;
wherein the first connection contact of the laser diode is coupled to the first metallization of the coupling capacitance; and
wherein the bias current is coupled to the first metallization of the coupling capacitance and the modulation current is coupled to the second metallization of the coupling capacitance.
8. The laser diode assembly of claim 7 , wherein the laser diode is formed on the first metallization of the coupling capacitance such that the first connection contact makes electrical contact thereto.
9. The laser diode assembly of claim 8 , further comprising a second coupling capacitance formed within the semiconductor body and defining first and second surfaces, wherein the first surface is associated with the surface of the semiconductor body and the second surface resides within the semiconductor body, the second coupling capacitance further comprising first and second metallizations associated with the first and second surfaces, respectively;
wherein the laser driver circuit is further configured to provide a second bias current and a second modulation current;
wherein the second bias current is coupled to the first metallization of the second coupling capacitance, and the second modulation current is coupled to the second metallization of the second coupling capacitance; and
wherein the first metallization of the second coupling capacitance is coupled to the second connection contact of the laser diode.