The N7788C combines a polarimeter and polarization controller for flexible lab use and fast spectral DGD/PMD and PDL measurement of optical components and fibers using a single-sweep algorithm with a Keysight tunable laser.
HIGHLIGTHS
- Highest accuracy in a single sweep. No averaging over multiple sweeps required
- No limitation of optical path length of component
- 1240 nm to 1650 nm operating wavelength range
- 1 MHz maximum sampling rate
- 0 ps to 1000 ps DGD measurement range
- 0 ps to 300 ps PMD measurement range
- 1.5° SOP measurement uncertainty
- ±2% DOP measurement uncertainty
The N7788C optical component analyzer provides both polarization control and analysis functions in one instrument for flexible laboratory use. The N7788C is especially used in combination with a tunable laser for measuring how an optical component changes the SOP of a signal. This measurement uses the unique single-sweep polarization dependent method to determine the parameters polarization mode dispersion (PMD) or differential group delay (DGD) and polarization dependent loss (PDL), based on a generalization of the standardized Jones Matrix Eigenanalysis method (JME).
For these spectral measurements of polarization dependent loss and dispersion, the N7788C is combined with a tunable laser and a new N7700 software engine. The LS engine, part of the Photonic Application Suite, now supports these measurements of wavelength-dependent DGD and PMD. This mode can be licensed with N7700103C PMD.
Parameters provided by this measurement include:
- DGD/PMD
- PDL
- Power/loss
- TE/TM-loss
- Jones matrices
- Mueller matrices
- 2nd-order PMD (depolarization + PCD)
The instrument comes in a compact form factor of just one rack unit height, with LAN and USB interfaces.
| Operating wavelength range 1 | 1240 nm to 1650 nm | |||
| Specification wavelength ranges | 1270 – 1350 nm | 1450 nm – 1620 nm | ||
| DGD measurement uncertainty 2, 9 | Typical 50 fs ± 0.6% of measured DGD at 2.0 nm resolution Typical 50 fs ± 3.0% of measured DGD at 0.1 nm resolution | |||
| DGD measurement range 9 | 0 ps to 1000 ps | |||
| PMD error 3, 9 | Typical 25 fs ± 2.0% of measured PMD | |||
| PMD repeatability 3, 9 | Typical ± 4 fs | |||
| PMD measurement range 3, 9 | 0 ps to 300 ps | |||
| PDL measurement uncertainty, typical 4, 9, 10 | ± (0.10 dB + 4% of measured PDL) | ± (0.05 dB + 4% of measured PDL) | ||
| PDL measurement repeatability 9 | Typical ± 0.01 dB | |||
| Insertion loss measurement range 3, 9 | Typical > 41 dB (for higher TLS power levels, increase value accordingly) | |||
| Specification wavelength ranges | 1270 – 1375 nm | 1375 – 1490 nm | 1490 – 1620 nm | |
| SOP measurement uncertainty 5, 6 | Typical 1.5° | |||
| DOP measurement uncertainty 5 | ± 2% Typical ± 1.5% | |||
| Insertion loss including reference connectors | Typical < 6.0 dB | Typical < 5.0 dB (1375 – 1460 nm) | < 5.0 dB (< 4.5 dB at 1550 nm) Typical < 4.5 dB (< 4.0 dB at 1550 nm) | |
| Sensitivity of output power to changing the SOP, peak-peak 8 | Typical < 1.5 dB | Typical < 1.0 dB | Typical < 0.4 dB (< 0.15 dB at 1550 nm) | |
| Relative power measurement uncertainty due to PDL 5 | ± 0.15 dB Typical ± 0.07 dB | ± 0.1 dB Typical ± 0.065 dB | ± 0.1 dB Typical ± 0.06 dB | |
| Relative power measurement error due to other factors 5 | Typical ± 0.1 dB | |||
| Input power range | –50 dBm to +7 dBm | |||
| Maximum safe input power | +12 dBm at polarimeter input +15 dBm at scrambler input | |||
| SOP cycling time (τ90 7) | < 10 μs | |||
- Range of calibration data.
- DUT properties: Insertion loss < 30 dB, PDL < 1 dB, DGD < 150 ps. PER of source > 23 dB.
- DUT properties: Insertion loss < 41 dB, PDL < 3 dB. Specification is typical for PMD > 50 ps. Applies for highly mode-coupled devices such as single mode fibers. Specification applies for PMD being averaged DGD over a wavelength span of max. 100 nm.
- DUT properties: Insertion loss < 25 dB, PDL < 6 dB. Note: DUT connectors are considered as being part of the DUT. Thus, angled connectors will add to the device’s PDL.
- Using polarimeter input for measurement. Input power > –30 dBm, averaging time > 10 μs, PDL excluding connector.
- DOP = 100%.
- Sequence with Stokes vector angles 0° – 90° – 180° – 90° – 0° with 50 kHz. Power range ≥ –10 dBm.
- At constant input power and input state of polarization (SOP).
- Valid only with Keysight 81600B, 8160xA and N777xC tunable laser sources: TLS power set to –6 dBm or higher; sweep over specification wavelength range.
- Verified at PDL of 0.4 dB.