A 3.45 Gigabits/s SiPM-Based OOK VLC Receiver

The journal version of my first paper, invited for IEEE Photonics Technology Letters. Alongside the 3.45 Gbps result it adds a model of the current a SiPM draws to hold its bias voltage, which predicts both its saturation and its power consumption.

Abstract

A relationship between irradiance and the current needed to maintain the bias voltage applied to a silicon photomultiplier (SiPM) is shown to agree with experimental data. In addition to showing the saturation of the SiPMs response this relationship can be used to determine the power consumed by an SiPM. In addition, results are presented which show that, because of its higher maximum photon count rate, a 30020 SiPM can achieve a bit error rate (BER) of $10^{-3}$ at a data rate of 3.45 Gbits/s.

Key Findings

Data transmission experiments show that the onsemi J-30020 SiPM outperforms the J-30035 because of its higher output pulse rate. The paper also considers what future receivers will need to reach higher data rates.

The bias current a SiPM sinks as a consequence of the light falling upon it can be expressed as:

$$I_{\text{bias}} = \frac{Q_{\text{cell}} N_{\text{cells}}\alpha(L+L_{\text{dark}})}{1 + \alpha \tau_{\text{recharge}} (L+L_{\text{dark}})}$$

In this expression, $Q_{\text{cell}}, N_{\text{cells}}, \tau_{\text{recharge}}$ and $L_{\text{dark}}$ are the charge needed to recharge a microcell, the number of microcells, the recharge time and the irradiance that is equivalent to the dark count rate of the SiPM.

And $\alpha$ is defined as: $$\alpha = \frac{\eta A_{\text{SiPM}}}{E_p}$$ Where $A_{\text{SiPM}}$ , $\eta$ , and $E_p$ are the area of the SiPM, the photon detection efficiency and the photon energy.

The same model explains the saturation behind the ISI paper.