NORME INTERNATIONALE CEI IEC INTERNATIONAL STANDARD 61290 5 1 Deuxième édition Second edition 2006 05 Amplificateurs optiques – Méthodes d''''essais – Partie 5 1 Paramètres de réflectance – Méthode d''''ana[.]
Réflectance maximale et minimale à l’entrée
This method allows for the precise determination of the input reflectance of the optical amplifier (OA) using an optical coupler and an optical isolator with known insertion loss To accurately assess the input reflectance, it is essential to appropriately discriminate and subtract the contribution of the amplified spontaneous emission (ASE) power, \( P_{ASE} \), at the signal wavelength The measurement procedures outlined below must be followed.
SOURCE OPTIQUE a) Mesure de la source optique par un mesureur de puissance optique
SOURCE OPTIQUE b) Mesure optique d’un coupleur et d’un isolateur
Figure 2 – Montage pour la mesure de la perte d’insertion du coupleur et de l’isolateur
Optical fibre jumpers must have a mode field diameter closely matching that of the input and output ports of the optical amplifier (OA), with a reflectance lower than –40 dB and a length not exceeding 2 m When directly connected to the OA, the jumper's connector should match the OA port characteristics Optical connectors should exhibit a connection loss repeatability better than ±0.2 dB and a reflectance below –60 dB Terminated ports must also maintain a reflectance lower than –60 dB The polarization controller should effectively convert any signal's state of polarization to another, utilizing either an all-fibre design or a combination of a quarter-wave plate and a half-wave plate, with a reflectance under –50 dB at each port and an insertion loss change of less than 0.1 dB.
The OA shall operate at nominal specified operating conditions Care shall be taken in maintaining the state of polarization of the input light during the measurement
The reflectance at each port of the optical amplifier (OA) is influenced by the device's intrinsic gain, which varies with the optical gain and is affected by both signal and pump power.
6.1 Maximum and minimum input reflectance
This method allows for the accurate determination of OA input reflectance by utilizing an optical coupler and an optical isolator with a known insertion loss To ensure precise input reflectance measurement, it is essential to identify and subtract the contribution of the reverse ASE power, \$P_{ASE}\$, at the signal wavelength The following measurement procedures must be adhered to for reliable results.
OPTICAL SOURCE a) Source optical power measurement
OPTICAL SOURCE b) Optical coupler and isolator output power measurement
Figure 2 – Set-up for insertion loss measurement of optical coupler and isolator
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DE PUISSANCE OPTIQUE dB a) Mesure de la puissance à l’entrée de l’AFO avec le mesureur de puissance optique
ISOLATEUR OPTIQUE dB b) Mesure de la puissance à l’entrée de l’AFO avec l’analyseur de spectre optique
Figure 3 – Montage pour les mesures de puissance à l’entrée de l’OA
6.1.1.1 Mesure des pertes d’insertion du coupleur optique, de l’isolateur et des connecteurs en utilisant un mesureur de puissance
To determine the insertion loss between ports 3 and 2 of the optical coupler and the optical isolator, set the optical source to the specified measurement wavelength and measure the optical source power, P3, using an optical power meter, as shown in Figure 2a.
Connect the optical source to port 3 of the coupler and the optical isolator to port 2 of the coupler Measure the optical power at the output of the isolator, denoted as P 3 ', using an optical power meter, as shown in Figure 2b, after completing the connections for ports 1 and 4 of the coupler.
6.1.1.2 Mesure de réflectance d’entrée à l’aide d’un analyseur de spectre optique
Calibrate the test setup by measuring the maximum retroreflected optical power, denoted as \$P_{cal}\$, that does not originate from the optical assembly (OA), as shown in Figure 1, but without the OA in place, and complete the port.
3 du coupleur en utilisant le contrôleur de polarisation pour préciser la puissance réfléchie maximale
6.1.1.3 Détermination de la puissance à l’entrée de l’OA
To measure the input power at the optical amplifier (OA), use an optical power meter for calibration, as shown in Figure 3a Adjust the variable optical attenuator to deliver the specified optical power, P in, according to the relevant specifications For calibrating the optical spectrum analyzer, measure the input power P in using the optical spectrum analyzer, as illustrated in the figure.
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VARIABLE OPTICAL ATTENUATOR a) OFA input power measurement with optical power meter
VARIABLE OPTICAL ATTENUATOR b) OFA input power measurement with optical spectrum analyzer
Figure 3 – Set-up for OA input power measurements
6.1.1.1 Measurement of optical coupler, isolator, and connectors insertion losses with a power meter
To assess the insertion loss between ports 3 and 2 of the optical coupler and isolator, configure the optical source to the designated measurement wavelength outlined in the specifications Measure the source optical power, denoted as P3, using an optical power meter, as illustrated in Figure 2a.
Connect the optical source to port 3 of the coupler and the optical isolator to port 2, then measure the output optical power, P 3', at the isolator using an optical power meter, as illustrated in Figure 2b, while ensuring that ports 1 and 4 of the coupler are terminated.
6.1.1.2 Measurement of input reflectance with an optical spectrum analyzer
To calibrate the test setup, measure the maximum optical power reflected backward, denoted as \$P_{cal}\$, without the optical amplifier (OA) This involves terminating coupler port 3 and utilizing the polarization controller to identify the peak reflected power, as illustrated in Figure 1.
6.1.1.3 Determination of the OA input power
To calibrate the optical spectrum analyzer, first measure the OA input power using an optical power meter, as illustrated in Figure 3a Set the variable optical attenuator to achieve the specified OA input optical power \( P_{\text{in}} \) Next, confirm the OA input power \( P_{\text{in}} \) with the optical spectrum analyzer, as depicted in Figure 3b.
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6.1.2 Mesure de la réflectance de l’OA
Insert the OA as shown in Figure 1 and measure the maximum and minimum reflected power of the OA, denoted as P MAX and P MIN, at the signal wavelength by adjusting the polarization controller to its maximum and minimum values Additionally, at the polarization controller settings corresponding to P MAX and P MIN, record the maximum and minimum ASE power, P ASEMAX and P ASEMIN, respectively, using the optical spectrum analyzer at the output of the isolator, as illustrated in Figure 1.
Different techniques can be applied to measure the ASE level One method involves interpolation to accurately determine the ESA level at the wavelength of the signal displayed on the optical spectrum analyzer Another technique utilizes a polarizer to eliminate the output signal component from the OA, allowing for the measurement of the ESA level without the influence of the amplified signal's spectrum When using the polarizer technique, it is essential that the optical signal at the input is linearly polarized with an extinction ratio better than 30 dB If the polarizer technique does not sufficiently reduce the signal power, interpolation can be used in conjunction with the polarizer method.
NOTE 2 En réglant l’atténuateur optique variable installé en aval de la source optique, la mesure peut être répétée à différents niveaux de la puissance à l’entrée.
Réflectance à la sortie
Réflectance maximale et minimale à l’entrée
La réflectance à l’entrée de l’OA doit être calculée comme suit: a) déterminer la perte d’insertion A du coupleur optique et celle de l’isolateur:
A = P 3 ' / P 3 (en unités linéaires) b) déterminer la puissance réfléchie maximale et minimale du signal de l’OA, P RMAX et P RMIN ,:
P RMAX = (P MAX – P ASEMAX – P cal ) / A (en unités linéaires)
P RMIN = (P MIN – P ASEMIN – P cal ) / A (en unités linéaires) c) calculer la réflectance d’entrée maximale et minimale de l’OA, R MAX et R MIN :
R MAX = 10 log (P RMAX / P in ) (en décibels)
R MIN = 10 log (P RMIN / P in ) (en décibels)
NOTE 1 La réflectance mesurée inclut aussi la réflectance des connecteurs d’entrée et de sortie
NOTE 2 La réflectance mesurée peut dépendre fortement du gain de l'OA
NOTE 3 L’incertitude de la mesure est supposée meilleure que ±1 dB (‡).
Réflectance à la sortie
Réflectance maximale et minimale à l’entrée
Les précisions suivantes doivent être présentées: a) la configuration du montage d’essai;
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Insert the optical attenuator (OA) as depicted in Figure 1 and measure the maximum and minimum OA reflected power, denoted as P MAX and P MIN, by adjusting the polarization controller for optimal values Additionally, at the polarization controller settings that yield P MAX and P MIN, document the corresponding reverse amplified spontaneous emission (ASE) maximum and minimum power, labeled as P ASEMAX and P ASEMIN, using the optical spectrum analyzer at the output of the isolator, as illustrated in Figure 1.
Different techniques for measuring Amplified Spontaneous Emission (ASE) levels are available One method utilizes an interpolation procedure to assess the ASE level at the signal wavelength displayed on an optical spectrum analyzer Alternatively, a polarizer can be employed to remove the signal component from the optical amplifier output, allowing for ASE measurement without interference from the amplified signal spectrum For this polarizer technique, the input optical signal must be linearly polarized with an extinction ratio exceeding 30 dB If the polarizer does not adequately eliminate the signal power, the interpolation technique can be used in conjunction with the polarizer method.
NOTE 2 The measurement can be repeated at different levels of input power adjusting the variable optical attenuator placed after the optical source
7.1 Maximum and minimum input reflectance
The input OA reflectance shall be calculated as follows: a) determine the optical coupler and isolator insertion loss, A, as:
A = P 3 ' / P 3 (in linear units) b) determine the maximum and minimum reflected signal power from the OA, P RMAX and P RMIN , as:
P RMAX = (P MAX – P ASEMAX – P cal) / A (in linear units)
P RMIN = (P MIN – P ASEMIN – P cal) / A (in linear units) c) calculate the maximum and the minimum input OA reflectance, R MAX and R MIN ,as:
R MAX = 10 log (P RMAX / P in) (in decibels)
R MIN = 10 log (P RMIN / P in ) (in decibels)
NOTE 1 The measured reflectance also includes the input and output connectors reflectance
NOTE 2 The measured reflectance can strongly depend on the OA gain
NOTE 3 The measurement uncertainty is expected to be better than ±1 dB (‡)
8.1 Maximum and minimum input reflectance
The following details shall be presented: a) arrangement of the test set-up;
This document is licensed to MECON Limited for internal use in Ranchi and Bangalore, provided by the Book Supply Bureau It includes essential specifications such as the spectral line width of the optical source (full width at half maximum), the optical pump power (if applicable), ambient temperature (if requested), input optical power (P in), the resolution bandwidth of the electrical spectrum analyzer, the measurement wavelength, and the maximum and minimum input reflectance.
Maximum and minimum input reflectance
This method allows for the accurate determination of OA input reflectance by utilizing an optical coupler and an optical isolator with a known insertion loss To ensure precise input reflectance measurement, it is essential to identify and subtract the contribution of the reverse ASE power, \$P_{ASE}\$, at the signal wavelength The following measurement procedures must be adhered to for reliable results.
OPTICAL SOURCE a) Source optical power measurement
OPTICAL SOURCE b) Optical coupler and isolator output power measurement
Figure 2 – Set-up for insertion loss measurement of optical coupler and isolator
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DE PUISSANCE OPTIQUE dB a) Mesure de la puissance à l’entrée de l’AFO avec le mesureur de puissance optique
ISOLATEUR OPTIQUE dB b) Mesure de la puissance à l’entrée de l’AFO avec l’analyseur de spectre optique
Figure 3 – Montage pour les mesures de puissance à l’entrée de l’OA
6.1.1.1 Mesure des pertes d’insertion du coupleur optique, de l’isolateur et des connecteurs en utilisant un mesureur de puissance
To determine the insertion loss between ports 3 and 2 of the optical coupler and the optical isolator, set the optical source to the specified measurement wavelength and measure the optical source power, P3, using an optical power meter, as shown in Figure 2a.
Connect the optical source to port 3 of the coupler and the optical isolator to port 2 of the coupler Measure the optical power at the output of the isolator, denoted as P 3 ', using an optical power meter, as shown in Figure 2b, after completing the connections for ports 1 and 4 of the coupler.
6.1.1.2 Mesure de réflectance d’entrée à l’aide d’un analyseur de spectre optique
Calibrate the test setup by measuring the maximum retroreflected optical power, denoted as \$P_{cal}\$, that does not originate from the optical assembly (OA), as shown in Figure 1, but without the OA, and complete the port.
3 du coupleur en utilisant le contrôleur de polarisation pour préciser la puissance réfléchie maximale
6.1.1.3 Détermination de la puissance à l’entrée de l’OA
To measure the input power at the optical amplifier (OA), use an optical power meter for calibration, as shown in Figure 3a Adjust the variable optical attenuator to deliver the specified optical power, P in, according to the relevant specifications For calibrating the optical spectrum analyzer, measure the input power P in using the optical spectrum analyzer, as illustrated in the figure.
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VARIABLE OPTICAL ATTENUATOR a) OFA input power measurement with optical power meter
VARIABLE OPTICAL ATTENUATOR b) OFA input power measurement with optical spectrum analyzer
Figure 3 – Set-up for OA input power measurements
6.1.1.1 Measurement of optical coupler, isolator, and connectors insertion losses with a power meter
To assess the insertion loss between ports 3 and 2 of the optical coupler and isolator, configure the optical source to the designated measurement wavelength outlined in the specifications Then, measure the source optical power, P3, using an optical power meter, as illustrated in Figure 2a.
Connect the optical source to port 3 of the coupler and the optical isolator to port 2 Measure the optical power at the output of the isolator, denoted as P 3', using the optical power meter, while ensuring that ports 1 and 4 of the coupler are terminated, as illustrated in Figure 2b.
6.1.1.2 Measurement of input reflectance with an optical spectrum analyzer
To calibrate the test setup, measure the maximum optical power reflected backward, denoted as \$P_{cal}\$, without the optical amplifier (OA) This involves terminating coupler port 3 and utilizing the polarization controller to identify the peak reflected power, as illustrated in Figure 1.
6.1.1.3 Determination of the OA input power
To calibrate the optical system, first measure the OA input power using an optical power meter, as illustrated in Figure 3a, and adjust the variable optical attenuator to achieve the specified OA input optical power \( P_{\text{in}} \) Next, calibrate the optical spectrum analyzer by measuring the OA input power \( P_{\text{in}} \) with it, as depicted in Figure 3b.
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6.1.2 Mesure de la réflectance de l’OA
Insert the OA as shown in Figure 1 and measure the maximum and minimum reflected power of the OA, denoted as P MAX and P MIN, respectively, at the signal wavelength by adjusting the polarization controller to its maximum and minimum values Additionally, at the polarization controller settings corresponding to P MAX and P MIN, record the maximum and minimum ASE power, P ASEMAX and P ASEMIN, respectively, using the optical spectrum analyzer at the output of the isolator, as illustrated in Figure 1.
Different techniques can be applied to measure the ASE level One method involves interpolation to accurately determine the ESA level at the wavelength of the signal displayed on the optical spectrum analyzer Another technique utilizes a polarizer to eliminate the output signal component from the OA, allowing for the measurement of the ESA level without the influence of the amplified signal spectrum When using the polarizer technique, it is essential that the input optical signal is linearly polarized with an extinction ratio better than 30 dB If the polarizer technique does not sufficiently reduce the signal power, interpolation can be used in conjunction with the polarizer method.
NOTE 2 En réglant l’atténuateur optique variable installé en aval de la source optique, la mesure peut être répétée à différents niveaux de la puissance à l’entrée
7.1 Réflectance maximale et minimale à l’entrée
La réflectance à l’entrée de l’OA doit être calculée comme suit: a) déterminer la perte d’insertion A du coupleur optique et celle de l’isolateur:
A = P 3 ' / P 3 (en unités linéaires) b) déterminer la puissance réfléchie maximale et minimale du signal de l’OA, P RMAX et P RMIN ,:
P RMAX = (P MAX – P ASEMAX – P cal ) / A (en unités linéaires)
P RMIN = (P MIN – P ASEMIN – P cal ) / A (en unités linéaires) c) calculer la réflectance d’entrée maximale et minimale de l’OA, R MAX et R MIN :
R MAX = 10 log (P RMAX / P in ) (en décibels)
R MIN = 10 log (P RMIN / P in ) (en décibels)
NOTE 1 La réflectance mesurée inclut aussi la réflectance des connecteurs d’entrée et de sortie
NOTE 2 La réflectance mesurée peut dépendre fortement du gain de l'OA
NOTE 3 L’incertitude de la mesure est supposée meilleure que ±1 dB (‡)
8.1 Réflectance maximale et minimale à l’entrée
Les précisions suivantes doivent être présentées: a) la configuration du montage d’essai;
LICENSED TO MECON Limited - RANCHI/BANGALORE FOR INTERNAL USE AT THIS LOCATION ONLY, SUPPLIED BY BOOK SUPPLY BUREAU.
Insert the optical attenuator (OA) as depicted in Figure 1 and measure the maximum and minimum OA reflected power, denoted as P MAX and P MIN, by adjusting the polarization controller for optimal values Additionally, at the polarization controller settings that yield P MAX and P MIN, document the corresponding reverse amplified spontaneous emission (ASE) maximum and minimum power, labeled as P ASEMAX and P ASEMIN, using the optical spectrum analyzer at the output of the isolator, as illustrated in Figure 1.
Different techniques are available for measuring Amplified Spontaneous Emission (ASE) levels One method utilizes an interpolation procedure to assess the ASE level at the signal wavelength displayed on an optical spectrum analyzer Alternatively, a polarizer can be employed to remove the signal component from the output of the optical amplifier, allowing for an accurate measurement of the ASE level without interference from the amplified signal spectrum For this polarizer technique to be effective, the input optical signal must be linearly polarized with an extinction ratio exceeding 30 dB If the polarizer does not adequately eliminate the signal power, the interpolation technique can be used in conjunction with the polarizer method.
NOTE 2 The measurement can be repeated at different levels of input power adjusting the variable optical attenuator placed after the optical source.
Output reflectance
Maximum and minimum input reflectance
The input OA reflectance shall be calculated as follows: a) determine the optical coupler and isolator insertion loss, A, as:
A = P 3 ' / P 3 (in linear units) b) determine the maximum and minimum reflected signal power from the OA, P RMAX and P RMIN , as:
P RMAX = (P MAX – P ASEMAX – P cal) / A (in linear units)
P RMIN = (P MIN – P ASEMIN – P cal) / A (in linear units) c) calculate the maximum and the minimum input OA reflectance, R MAX and R MIN ,as:
R MAX = 10 log (P RMAX / P in) (in decibels)
R MIN = 10 log (P RMIN / P in ) (in decibels)
NOTE 1 The measured reflectance also includes the input and output connectors reflectance
NOTE 2 The measured reflectance can strongly depend on the OA gain
NOTE 3 The measurement uncertainty is expected to be better than ±1 dB (‡).
Output reflectance
Maximum and minimum input reflectance
The following details shall be presented: a) arrangement of the test set-up;
The optical source's spectral line width (full width at half maximum) is crucial, along with the optical pump power indication (if applicable), ambient temperature (if requested), and the input optical power, P in Additionally, the resolution bandwidth of the electrical spectrum analyzer, the measurement wavelength, and the maximum and minimum input reflectance are important parameters to consider.
This document is licensed to MECON Limited for internal use in Ranchi and Bangalore, provided by the Book Supply Bureau Key parameters include the spectral linewidth of the optical source, the optical pump power, ambient temperature, input signal optical power (P in), resolution bandwidth of the optical spectrum analyzer, measurement wavelength, and the maximum and minimum input reflectance.
Output reflectance
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