PT-9610

Measurement of noise proportion in Laser power (radiant power)

In most laser power measurement applications radiant laser power is the one and only qualifying parameter. However in a few specific applications the radiant power noise characteristic is of interest as well. Typically in these applications the detector bandwidth cannot be limited to reduce the signal noise through long integration times. One common example of this involves laser imaging scanners. The very high scanning frequency of these systems requires very fast detection systems without bandwidth limitation. Because of this the noise level and noise characteristic of the laser, used as a light source, influences the signal to noise ratio and therefore the imaging resolution.

Six measurement modes for noise evaluation 

In 1996 Gigahertz-Optik developed the PT-9610 in close cooperation with a main manufacturer of laser imaging scanners to design a simple to use mobile meter for production and field service use. Eventually the PT-9610 became a reference standard for laser manufacturers supplying lasers for this type of application. The PT-9610 operates in two basic modes. Laser power is measured in CW mode. Plus power oscillation about the mean value (modulation component) is measured and can be analyzed in six different ways:

• r.m.s. wide band value - up to 1 MHz
• r.m.s low frequency value - 830Hz (-3dB), 480 Hz (-1.5dB)
• r.m.s. high frequency value - 280Hz (-3dB), 480 Hz (-1.5dB)
• positive peak value
• negative peak value
• peak to peak value

Low profile detector head for measurement in tight spaces 

The PT-9610’s PD-2T laser power detector is low profile only 8mm high with a removable grip for easy placement into tight spaces like inside equipment. Its unique design which includes a miniature integrating sphere made from synthetic ODM98 coating and fast PIN silicon photodiode provide a detection range of up to 120 mW and 1 MHz.

Traceable calibration 

Radiant power sensitivity calibration is provided from 350 nm to 650 nm in 10 nm steps and at 351 nm, 364 nm, 405 nm, 426 nm, 441 nm, 458 nm, 473 nm, 476 nm, 488 nm, 496 nm, 514 nm, 532 nm, 543 nm, 568 nm, 594 nm, 612 nm, 633 nm and 647 nm. The calibration data is stored in the detector calibration data connector.