The same power supply can drive multiple laser diodes if they are connected in series, but they must never be connected in parallel. When two diodes are connected in series, they will function properly as long as the compliance voltage is large enough to cover the voltage drop. My reading suggests that laser diodes need to be run in series in order to achieve a balanced load across both LDs, so as not to overdrive one and underdrive the other - with catastrophic results. Series connection means a side by side connection. When two components are connected in. Two series-connected diodes with reverse bias: In practice, the $v-i$ characteristics for the same type of diodes differ due to tolerances in their production process Under forward-biased conditions, both diodes conduct equal amounts of current, with nearly identical forward voltage drops. However. Connecting diodes in series (AK-AK --|<--|<--) will increase the forward voltage of the resultant diode.
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