Optical transceiver, optical transceiver module using the same, and test method for optical transceiver
An optical transceiver has a first optical waveguide connected to an input/output port for signal light, a second optical waveguide configured to input and output test light, an optical circuit configured to perform optical-to-electrical conversion or electrical-to-optical conversion, and an optical switch provided between the optical circuit and the first and the second optical waveguides and configured to switch between a first path connecting the optical circuit to the first optical waveguide and a second path connecting the optical circuit to the second optical waveguide, wherein the optical switch is configured to select the second path in an ON state with an electrical voltage being applied to the optical switch, and select the first path in an OFF state without the electrical voltage being applied to the optical switch.
1. An optical transceiver comprising:
a first optical waveguide connected to an input/output port for signal light;
a second optical waveguide configured to input and output test light;
an optical circuit configured to perform optical-to-electrical conversion or electrical-to-optical conversion; and
an optical switch provided between the optical circuit and the first and the second optical waveguides and configured to switch between a first path connecting the optical circuit to the first optical waveguide and a second path connecting the optical circuit to the second optical waveguide,
wherein the optical switch is configured to select the second path in an ON state with an electrical voltage being applied to the optical switch, and select the first path in an OFF state without the electrical voltage being applied to the optical switch.
2. The optical transceiver as claimed in claim 1 , wherein the optical switch is of a Mach-Zehnder type, a double ring type, a multimode interference type, or a total reflection type.
3. The optical transceiver as claimed in claim 1 , wherein output of the optical switch is connected to a cross port in the OFF state, and connected to a bar port in the ON state.
4. The optical transceiver as claimed in claim 1 , wherein the optical switch is provided with electrode pads that are electrically short-circuited.
5. The optical transceiver as claimed in claim 4 , wherein each of the electrode pads is short-circuited by a bonding wire.
6. The optical transceiver as claimed in claim 4 , wherein the electrode pads are arranged close to each other in an array and short-circuited collectively by a conductive adhesive.
7. The optical transceiver as claimed in claim 4 , further comprising:
a board on which a ground terminal is provided,
wherein the electrode pads of the optical switch are connected to the ground terminal.
8. The optical transceiver as claimed in claim 4 , further comprising:
a ground pad positioned adjacent to the electrode pads of the optical switch; and
a board on which a ground terminal is provided,
wherein the electrodes pads and the ground pad are electrically connected to each other by a conductive adhesive, and the ground pad and the ground terminal are connected by a bonding wire.
9. The optical transceiver as claimed in claim 1 , wherein an ON voltage of the optical switch is set higher than a drive voltage of the optical circuit.
10. The optical transceiver as claimed in claim 9 , wherein an electrode length of the optical switch is shorter than an electrode length of a switch used in the optical circuit.
11. An optical transceiver module comprising:
an optical transceiver having
a first optical waveguide connected to an input/output port for signal light,
a second optical waveguide configured to input and output test light,
an optical circuit configured to perform optical-to-electrical conversion or electrical-to-optical conversion, and
an optical switch provided between the optical circuit and the first and the second optical waveguides and configured to switch between a first path connecting the optical circuit to the first optical waveguide and a second path connecting the optical circuit to the second optical waveguide, the optical switch being configured to select the second path in an ON state with an electrical voltage being applied to the optical switch and select the first path in an OFF state without the electrical voltage being applied to the optical switch;
a package configured to accommodate the optical transceiver;
a light source provided in the package; and
a digital signal processor provided in the package and connected to the optical transceiver.
12. A test method for an optical transceiver comprising:
fabricating an optical transceiver having an optical circuit, a first optical waveguide connected to an input/output port for signal light, a second optical waveguide connected to an input/output interface for inputting and outputting test light, and an optical switch provided between the optical circuit and the first and the second optical waveguides, in a prescribed area on a wafer;
inputting and extracting the test light using the input/output interface;
applying a voltage to the optical switch to turn on the optical switch to connect the second optical waveguide to the optical circuit;
measuring the test light input to the optical circuit; and
turning off the voltage having been applied to the optical switch after measurement of the test light.
13. The test method as claimed in claim 12 , further comprising:
after the turning off the voltage, electrically short-circuiting electrode pads provided to the optical switch.