Low-loss phased-array based 4-channel wavelength demultiplexer integrated with photodetectors

Abstract

Abstract-A 4-channel phased-array wavelength division demultiplexer with 1.8 nm channel spacing at 1.54pm has been monolithidy integrated with photodetedors in WhGaAsP.On chip losses are 3.5 to 4.5 dB. These are the lowest losses reported so far for demultiplexers monolithically integrated with photodetectors. Nearest neighbor crosstalk ranges from -12 to -21 dB.

PHASAR-based WDM-devices: Principles, design and applications

“…From Fig. 1(b), it follows (after some manipulation) that (3) in which is the central frequency, is the (slab) mode index in the free propagation region, is the length increment of the array waveguides as described before, is the divergence angle between the array waveguides in the fan-in and fan-out sections, and is the group index of the waveguide mode, (4) It is seen that does not occur in the right-hand expression in (3) so that filling-in of the space between the array waveguides near the apertures due to a finite lithographical resolution does not affect the dispersive properties of the demultiplexer.…”

“…4) Coupling in the Array: Crosstalk can also be incurred by phase distortion due to coupling in the input and output sections in the arrays. It might be expected that this type of coupling will not heavily affect the focusing and dispersive properties of the array on similar grounds as mentioned under (3) and (4). The filling in of the gaps near the array apertures can be considered as introducing an extremely strong coupling in the input and output region, which obviously does not degrade the PHASAR performance [59].…”

“…InP-based demultiplexers cannot compete with silica-based devices with respect to fiber coupling loss, which makes them less suitable for realization of circuits with a low complexity. Their main advantage lies in their potential for monolithic integration of active components such as detectors [3], [4], [6], [74]- [76], [113], optical amplifiers and modulators [39]- [41], [108]- [112], [115], and switches [99], and their potential to integrate large numbers of components on a single chip.…”

GENERIC INP-BASED INTEGRATION TECHNOLOGY: PRESENT AND PROSPECTS (Invited Review)

“…It started with the publication of the first AWG by Smit [7] in 1988, followed by Takahashi et al (1990) [8] and Dragone (1991) [9]. After the invention of the AWG a number of AWG-based devices with increasing circuit complexity was reported: WDM receivers with 5-10 components by Amersfoort et al (1993) [10], Zirngibl et al (1995) [11] and Steenbergen et al (1996) [12]; WDM lasers with 10-20 components by Zirngibl et al ( , 1996 [13,14] and Staring et al (1996) [15]; WDM channel selectors with 10-20 components by [16], Ishii et al (1998) [17], Menezo et al (1999) [18], Mestric et al (2000) [19] and Kikuchi et al (2001) [20] and a crossconnect chip with 66 components by [21].…”

Monolithic Integration of Semiconductor Waveguide Optical Isolators with Distributed Feedback Laser Diodes

“…Representatives of these InP-based photonic integrated circuits are, electroabsorption modulator integrated distributed feedback laser diodes (DFB LDs) (Kawamura et al, 1987, H. Soda et al, 1990 and arrayed waveguide grating (AWG) integrated optical transmitters and receivers (Staring et al, 1996, Amersfoort et al, 1994. Recently, dense wavelength division multiplexing (DWDM) optical transmitters and receivers have been reported with large-scale photonic integrated circuits having more than 50 components in a single chip (Nagarajan et al, 2005).…”