On-Chip Optical Power Monitor Using Periodically Interleaved P-N Junctions Integrated on a Silicon Waveguide

Abstract

We investigate the photocurrent generation with surface-state absorption effect in a silicon waveguide integrated with periodically interleaved p-n junctions. Due to the high electric field (∼5 × 10 5 V/cm) and large depletion area coverage in the waveguide, our device can collect more photocurrent than regular p-i-n and p-n structures. The responsivity of our device is optical power dependent with a higher value at a lower power level. The measured 3-dB bandwidth of the frequency response is 11.5 GHz. Although its responsivity is low compared to that of III-V and Ge photodiodes, its simple fabrication and compatibility with allsilicon photonic devices makes it suitable as on-chip optical power monitors.

On-line monitor of the mode/polarization-division multiplexed channels on the silicon chip

“…The heavily doped p+/n+ region has a doping concentration of about 10 20 cm -3 . Rapid thermal annealing at 1030 ℃ is used after ion implantation activates the dopants and repairs damage in the silicon lattice without causing much dopant redistribution [13] . To balance the extra loss and responsibility, the length photodiodes are designed to be ~ 450 μm.…”

“…As the figure 3(a)(b) shows that one photodiode is located in the center of the waveguide, another one is located a few hundred microns from the center. Due to defect state absorption (DSA) effect [11][12] , the depletion area has larger electronic field and shows stronger responsibility [13] , so we can use this principle to detect the field distributions along the width. As figure 3(c)(d) shows, the field of the TE 0 mode is stronger in the center of waveguide, and at the contrary, the field of the TE1 mode is the weakest in the center and the strongest field is located 1/4 width away from center.…”

Visible-Light Integrated PIN Avalanche Photodetectors With High Responsivity and Bandwidth

“…As the PIN devices exhibit low I dark and high SNR, they could be a more suitable choice for applications that are sensitive to dark current levels and passive power consumption, such as optical power monitors in integrated photonic circuits [39], [40].…”

Breakthroughs in Photonics 2013: Toward Feedback-Controlled Integrated Photonics

“…In silicon photonics, the waveguide itself can be used as power monitor at 1550 nm, by exploiting photocarrier generation due to two photon absorption (TPA) [25], surface-state absorption (SSA) [26], and defect mediated absorption [27]. Although the loss introduced by these detectors can be relatively low [28], when many devices are integrated in a complex photonic circuit, the number of probing points increases accordingly [2], so that any light attenuation or perturbation should be avoided [29]. The development of transparent waveguide power monitors has been always considered one of the key challenges for integrated optical technology [29].…”