Abstract: A light emitting diode (LED) stack for a display including a substrate, a first LED stack disposed on the substrate, a second LED stack disposed on the first LED stack, a third LED stack disposed on the second LED stack, a first color filter interposed between the first LED stack and the second LED stack, and a second color filter interposed between the second LED stack and the third LED stack, in which the second LED stack and the third LED stack are configured to transmit light generated from the first LED stack to the outside, and the third LED stack is configured to transmit light generated from the second LED stack to the outside.

Abstract: A light emitting diode (LED) stack for a display including a substrate, a first LED stack disposed on the substrate, a second LED stack disposed on the first LED stack, a third LED stack disposed on the second LED stack, a first color filter interposed between the first LED stack and the second LED stack, and a second color filter interposed between the second LED stack and the third LED stack, in which the second LED stack and the third LED stack are configured to transmit light generated from the first LED stack to the outside, and the third LED stack is configured to transmit light generated from the second LED stack to the outside.

Abstract: A display apparatus including a thin film transistor (TFT) substrate; a first LED sub-unit, a second LED sub-unit, and a third LED sub-unit; first, second, third, and fourth electrode pads disposed between the TFT substrate and the first LED sub-unit; and connectors connecting the first, second, and third LED sub-units to a respective one of the electrode pads, in which the first, second, and third sub-units are configured to be independently driven; light generated from the first LED sub-unit is emitted to the outside of the display apparatus by passing through the second and third LED sub-units; light generated from the second LED sub-unit is emitted to the outside of the display apparatus by passing through the third LED sub-unit; and at least one of the connectors includes a first portion electrically connecting a first surface of the first LED sub-unit to the second electrode pad.

Abstract: Provided is an external cavity laser (ECL) including a vertical cavity surface emitting laser (VCSEL)-Distributed Bragg Reflector (DBR) type light emitting unit configured to receive a current and emit light, and including a DBR function layer and an active layer for a quantum well formed on one side of this DBR function layer, and an optical circuit unit including a light guide in which one end surface is installed to face an active layer at one side of the active layer, light generated from the active layer is received and guided, and an optical axis is formed vertically to an active layer plane, a reflection pattern that is formed at one side of the light guide so as to receive light output from the other end of the light guide to reflect the light again to the light guide, and an external layer for surrounding the light guide and the reflection pattern, wherein the VCSEL-DBR type light emitting unit and the optical circuit unit are mutually coupled to each other.

Abstract: Provided is an external cavity laser (ECL) including a vertical cavity surface emitting laser (VCSEL)-Distributed Bragg Reflector (DBR) type light emitting unit configured to receive a current and emit light, and including a DBR function layer and an active layer for a quantum well formed on one side of this DBR function layer, and an optical circuit unit including a light guide in which one end surface is installed to face an active layer at one side of the active layer, light generated from the active layer is received and guided, and an optical axis is formed vertically to an active layer plane, a reflection pattern that is formed at one side of the light guide so as to receive light output from the other end of the light guide to reflect the light again to the light guide, and an external layer for surrounding the light guide and the reflection pattern, wherein the VCSEL-DBR type light emitting unit and the optical circuit unit are mutually coupled to each other.

Abstract: A signal coupler (20) for a passive optical network (PON) system is disclosed. The coupler (20) includes a first port for two-way feeder side communication with a PON terminal (12), a star coupler (29), other ports (23) for two-way distribution side communication with each of plural remote optical network units (ONUs) (30), and a repeater (28) installed on the upstream signal path from the ONUs (30) to the PON terminal (12). Upstream signals from ONUs (30) are received by the repeater (28) without passing through the star coupler (29) by using a coarse wavelength division multiplexer (50) on each distribution fibre and taking out the upstream light before arrival at the star coupler (29) and redirecting it to a receiver array and multiplexer (52). The repeater (28) regenerates each upstream signal and changes its wavelength.

Abstract: An optical network (10) comprising a plurality of optical network units (12), an optical line terminal unit, and a first optical combiner unit (20), wherein the optical network units (12) are optically connected to the first optical combiner unit (20) via respective optical connections in a manner such that optical transmissions from the optical network units (12) are combined onto one optical line connection to the optical line terminal unit, a redirection unit (24) for redirecting a portion of a transmission signal on the optical line connection towards the first combiner unit (20) each optical network unit (12) comprising an optical transmitter unit (14) for transmitting an optical signal to the optical line terminal unit, and a CSMA/CD unit (16) arranged, in use, to tap off at least a portion of the redirected portion of the transmission signal from the optical connection between the optical network unit (12) and the first combiner unit (20), wherein the CSMA/CD unit (16) is further arranged to control th

Abstract: An optical drop structure comprising a multi-port optical circulator (MOC), a first reflection filter unit optically connected in series between a first port and a second port of the MOC, a second reflection filter unit optically connected in series between a third port and a fourth port of the MOC, and the optical drop structure is arranged, in use, in a manner such that, a first optical signal entering through a fifth port of the MOC is subjected to the first reflection filter unit and exits at a sixth port of the MOC and a reflected portion of the first optical signal exits at a seventh port of the MOC, and a second optical signal entering through the sixth port of the MOC is subjected to the second reflection filter unit and exits at the fifth port of the MOC and a reflected portion of the second optical signal exits at an eights port of the MOC.