V23832-T2131-M101

V23832-R121-M101

Laser Eye Safety

Data Sheet

12

2003-11-19

Laser Eye Safety

The transmitter of the AC coupled Parallel Optical Link (PAROLI) is an IEC 60825-1

Amend. 2 Class 1M laser product. It complies with FDA performance standards (21 CFR

1040.10 and 1040.11) for laser products except for deviations pursuant to Laser Notice

No. 50, dated July 26, 2001. To avoid possible exposure to hazardous levels of invisible

laser radiation, do not exceed maximum ratings.

The PAROLI module must be operated under the specified operating conditions (supply

voltage can be adjusted between 3.0 V and 3.6 V) under any circumstances to ensure

laser eye safety.

Class 1M Laser Product

Attention: Invisible laser radiation. Do not view directly with optical instruments.

Note: Any modification of the module will be considered an act of “manufacturing”, and will

require, under law, recertification of the product under FDA (21 CFR 1040.10 (i)).

Figure 6

Laser Emission

Laser Eye Safety Design Considerations

To ensure laser eye safety for all input data patterns each channel is controlled internally

and will be switched off if the laser eye safety limits are exceeded. A channel alerter

switches the respective data channel output off if the input duty cycle permanently

exceeds 57% (switching range 57 % min. - 65 % max.). The alerter will not disable the

channel below an input duty cycle of 57% under all circumstances.

The minimum alerter response time is 1 µs with a constant high input, i.e. in the input

pattern the time interval of excessive high input (e.g. ’1’s in excess of a 57% duty cycle,

consecutive or non-consecutive) must not exceed 1 µs, otherwise the respective channel

will be switched off. The alerter switches the respective channel from off to on without

the need of resetting the module if the input duty cycle is no longer violated.

All of the channel alerters operate independently, i.e. an alert within a channel does not

affect the other channels. To decrease the power consumption of the module unused

channel inputs can be tied to high input level. In this way a portion of the supply current

in this channel is triggered to shut down by the corresponding alerter.

Laser aperture

and beam

File: 3506