jgimenoiwm-12/1/2004 fiber optic module 1 studies and development of a first fiber optic module...

jgimeno IWM-12/1/2004 Fiber Optic module 1

STUDIES AND STUDIES AND DEVELOPMENT OF A DEVELOPMENT OF A FIRST FIBER OPTIC FIRST FIBER OPTIC MODULE PROTOTYPEMODULE PROTOTYPE

Javier Gimeno Vicente

IWM-12/1/2004 Fiber Optic module 2jgimeno

CONTENTSCONTENTS Why a Fiber Optic module? Characteristics of the link

• Attenuation: link between two BICs• Optical power budget analysis

Optical components “Detection and switch” TESTS

• BIDI MODULE solution• TRANSCEIVER MODULE solution• ELED or “Agilent” solution• DISCRETE BIDI solution

Conclusions Future works


Why a Fiber Optic module?• Beam Permit Loops• We don’t transmit data 10MHz control signal

• Freq = OK• No freq. = beam dump


Why a Fiber Optic module?

TTL or PLC Input

Beam InterlockClient Interfaces

InterfaceModule

CoreModule

Fiber OpticModule

PowerPC CPU(VMEbus Master)

VM

Eb

us

Control Network (Ethernet)

Open/CloseLoops

Beam PermitLoops

(fibre optics)

UTC data(via LHC Timing)

V M E C r a t e

TTL or PLC Input

TTL or PLC Input

Client#1

Client#2

Client#16

12

16

1 16

VMEVME CRATECRATEVMEVME CRATECRATEVME CRATE

up to 300m

• Responsible of receiving the Beam Permit signal (10MHz if OK), interrupting if a

client activates a beam dump request, and transmitting the resulting signal.• CONSTRAINTS: fast, simple and RELIABLE.• Fast requirements: to convert the light into voltage to interrupt (switch) the

signal to convert the signal into light.

Permit Loops

Switch

Permit Loops

Dump Request(from CORE)

OpticalTransmitter

OpticalReceiver


Characteristics of the link (1/2)

BIC layout in the LHC

LH

C T

UN

NE

L room

roomop

tical fiber

optical fiber

FO chassis

BIC

ROOM

BEAM INTERLOCK LOOPS

optical fiber

FO chassis

BIC BIC

LHC T

UNNEL

room

room

3.3Km

met

ers

ROOM

SAME ROOM: IP1, IP3, IP7 SAME PLACE: IP2, IP4, IP5, IP6, IP8 DIFFERENT PLACE = different IP (x8)


Characteristics of the link (2/2) Characteristics fixed and determined by:

• Fiber

• Distance between BICs

• Connectors

All the links must fulfil the

optical power budget rule

• Single mode suitable for 1310nm and 1550nm wavelengths

• Attenuation: 0.5dB/Km (worst case)

• Degradation during time negligible

• Typical delay of 5ns/m (worst case: half LHC (~13.5Km) ~67.5µs)

• max.: 3.3Km (BICs in different IPs)• min.: some meters (BICs in the same room)

• Any possible• Recommended and used at CERN: E2000/APC• Losses: 0.5dB in each connector (worst case)

TRANSMITTER'SMAXIMUMOPTICALPOWER

RECEIVER'SMINIMUM

SENSIBILITY

< _ MINIMUMATTENUATION

TRANSMITTER'SMINIMUMOPTICALPOWER

RECEIVER'SMAXIMUM

SENSIBILITY<

_ MAXIMUMATTENUATION

_ SAFETYMARGIN

RECEIVER'SALLOWABLE

POWERMARGIN


Attenuation: link between two BICs

SOURCES OF ATTENUATION

ATTENUATION QUANTITY RESULT

Fiber 0.5dB/Km ~ 3.3Km ~ 1.65dB

Connectors 0.5dB per connector 6 ~ 3dB

MAXI MUM ATTENUATI ON: ~ 4.65dB

SOURCES OF ATTENUATION

ATTENUATION QUANTITY RESULT

Fiber 0.5dB/Km ~ 0Km ~ 0dB

Connectors 0.5dB per connector 2 ~ 1dB

MI NIMUM ATTENUATION: ~ 1dB

Minimum attenuation: BICs in the same room

Maximum attenuation: BICs in different IPs

Safety margin min. 2dB typ. 3dB (Honeywell…)


OPTICALTRANSMITTER

OPTICALRECEIVER

TRANSMITTER'SMAXIMUM

OPTICAL POWER

MINIMUMOPTICALPOWER

RECEIVED

Connector(~0.5dB)

Fiber(0.5dB/Km)

min. sensibility

max. sensibility

opticalpower

lenght

safety margin

FIBER-OPTICCONNECTION

CHASSIS

MIN. ATTEN.

MAX. ATTENUATION

FIBER-OPTICCONNECTION

CHASSIS

OPTICALRECEIVER

MAXIMUMOPTICALPOWER

RECEIVED

2 conn.(~1dB)

2 conn.(~1dB)

Connector (~0.5dB)

Connector(~0.5dB)

RECEIVER’SMINIMUMALLOWABLEPOWERMARGIN

3.3Km

TRANSMITTER'SMINIMUM

OPTICAL POWER

Optical power budget analysis

Optical power margin rule

It determines the optical power characteristics of the transmitter and receiver

TRANSMITTER'SMAXIMUMOPTICALPOWER

RECEIVER'SMINIMUM

SENSIBILITY

< _ MINIMUMATTENUATION

TRANSMITTER'SMINIMUMOPTICALPOWER

RECEIVER'SMAXIMUM

SENSIBILITY<

_ MAXIMUMATTENUATION

_ SAFETYMARGIN

RECEIVER'SALLOWABLE

POWERMARGIN


Optical components (1/3) Types

Electrical characteristics• DISCRETE:

- Analog interface- Development of the analog to digital conversion

• MODULE:- Optical component + digital interface

Optical characteristics• OPTICAL TRANSMITTER:

- LED: Surface-emitting LED, Edge-emitting LED (ELED), Superluminescent LED (SLED)…- LASER: Laser Diode (LD), Vertical Cavity Surface-emitting Laser (VCSEL)…

• OPTICAL RECEIVER:- PIN (positive-intrinsic-negative) photodiode- Avalanche photodiode (APD)

ANALOG (CURRENT)SIGNAL

DIGITALELECTRICALINTERFACE

LED / LASERDRIVER

PREAMP(TIA)ANALOG (CURRENT)

SIGNAL

LIGHT

POSTAMP

DIGITALELECTRICALINTERFACE

ANALOG(VOLTAGE)

SIGNAL

DISCRETE RECEIVERWITHOUT TIA

DISCRETE RECEIVER WITH TIA

RECEIVER MODULE

DISCRETETRANSMITTER

TRANSMITTER MODULE


Optical components (2/3)

*WDM: Wave Division Multiplex

BIDIrectional TRANSCEIVER DETAIL

• TRANSCEIVER or TRANSMITTER AND RECEIVER:- Independent transmitter and receiver- 2 fibers to transmit and receive (same wavelengths)

• BI-DI TRANSCEIVER:- Transmitter and receiver in the same device- ONLY 1 fiber to transmit and receive (different wavelengths)

F.O. CABLE TX

F.O. CABLE RX

TX

RX

light <-> voltageCONVERSION

TRANSCEIVER

TX

RXlight <-> voltageCONVERSION

TRANSCEIVER

RX signals

TX signals

RX signals

TX signals

F.O. CABLETX&

RX


BI-DITRANSCEIVER

TX&

RX


BI-DITRANSCEIVER

RX signals

TX signals

RX signals

TX signals

Wavelength 1

Wavelength 1

Wavelength 1 Wavelength 2

2 topologies

using


Optical components (3/3)

SOLUTION CHARACTERISTICS COMPANY

BIDI MODULE SOLUTION

• 1 fiber to transmit and receiver• BIDI module (standard package)

ITEC

Infineon

TRANSCEIVER MODULE SOLUTION

• 2 fibers to transmit and receiver• Module component (standard package)

ITEC

ELED or “Agilent” SOLUTION

2 fibers to transmit and receiver Discrete components Agilent design

Agilent and PD-LD

DISCRETE BIDI SOLUTION

• 1 fiber to transmit and receiver• Discrete components• Development of analog to digital interface

Afonics

OTHER SOLUTIONS • S.I.Tech • ONTi • Eva Calvo• Cypress

Selection


DETECTION and SWITCH (1/2)

Not complex (but must be RELIABLE!!):

• SWITCH: simple AND gate

• Frequency Detection • “By edge”, using counters• “By sample”, using a shift register to sample

SwitchDump Request(from CORE)

OpticalTransmitter

OpticalReceiver

Switch

OpticalTransmitter

OpticalReceiver


Switch


FREQUENCYDETECTION

OpticalReceiver

Switch


OpticalTransmitter

SOURCE10MHz

To DUMPSYSTEM

FIRST BIC

SECOND BIC

LAST BIC

PENULTIMATE BIC

BEAM PERMITLOOP

F.O. module

F.O. moduleF.O. module

F.O. module


DETECTION and SWITCH (2/2) Proposed circuit for the TESTS

REGENERATIONNO REGENERATION REGENERATION

+ 1 source of 10MHz in the first BIC: if no RX signal (10 MHz) no TX signal+ TX signal depends on BEAM PERMIT SIGNAL and ENABLE signal± Redundancy: FREQUENCY DETECT, but adds an extra-delay

- Integrity of the 10 MHz signal has to be tested

+ Regeneration of the 10 MHz signal- 1 source in each BIC: no RX signal (10 MHz) ≠ no TX signal- TX signal depends only on TX ENABLE signal

- Less reliable

- REGENERATION -NEW SOURCE 10MHz

BEAM PERMITSIGNAL FREQUENCY

DETECT

ALARM(from CORE)

& BEAM PERMITSIGNAL ENABLE

BEAM PERMITSIGNAL

OPTICALRECEIVER

JUMPER

OPTICALTRANSMITTERSWITCH

REDUNDANCY (NO RG)


BIDI MODULE Solution (1/3)

DESIGN:• Very simple• Digital conversion

Prototype board

F.O. CABLETX&

RX

BI-DITRANSCEIVER

MODULE

RX signals

TX signals

ELECTRICALINTERFACE

TTL <--> PECL / LVPECL

FREQUENCYDETECTOR

&SWITCH

ALARM

DETECT

TX_TTL

RX_TTL

F.O. CABLETX&

RX

BI-DITRANSCEIVER

MODULE

RX signals

TX signals

ELECTRICALINTERFACE

TTL <--> PECL / LVPECL

FREQUENCYDETECTOR

&SWITCH

ALARM

DETECT

TX_TTL

RX_TTL


BIDI MODULE Solution (2/3) TESTS

• Without “detection and switch”• Without attenuator, only fiber optic cable of 10m

F.O. CABLETX&

RXRX signals

TX signals

F.O. CABLE

BIDI 1

Signal Detect

ELECTRICALINTERFACE 1

TTL <--> PECLRX

TX

SD

10m

TX&

RXRX signals

TX signals

BIDI 2

Signal Detect

ELECTRICALINTERFACE 2

TTL <--> PECLRX

TX

SD


BIDI MODULE Solution (3/3) RESULTS:

+ BIDI MODULES (ITEC and Infineon) fulfil the optical power budget rule (minimum transmitter output power -15dBm / Receiver sensibility: -33dBm)- RECEIVERS PROBLEM: AGC in TIAs don’t allow the transmission of signal below ~100kHz Not good “switch” from 10MHz to DC signal- Same results for TRANSCEIVER MODULE SOLUTION

CONCLUSION: SOLUTION(S) NOT GOOD

TX

RX

SD

TX

RX

SD


ELED or “Agilent” Solution (1/3)

DESIGN:• Agilent design• Simple but ELEDs quite expensive• ELEDs board standard package (it can be used with BIDI prototype board after some modifications)

Modified BIDI prototype board

FREQUENCYDETECTOR

&SWITCH

ALARM

DETECT

F.O. CABLE

F.O. CABLETX

Agilentboard

F.O. CABLE

F.O. CABLERX

TXAgilentboard

RX

Atten. Atten.

TX_TTL

Modified BIDI prototype board

RX_TTL

FREQUENCYDETECTOR

&SWITCH

ALARM

DETECT

TX_TTL

RX_TTL



FIRST TEST: transmission, attenuation and detection

RESULTS:+ PD-LD ELED with Agilent receiver fulfill the optical power budget rule (minimum transmitter output power -23dBm / Receiver sensibility: -33dBm)+ Max. attenuation: 12dB + REGENERATION is not necessary+ Lost of frequency correctly detected

TX

RX

DETECT

TX

RX



SECOND TEST: beam permit loop simulation

CONCLUSION: SOLUTION WORKING

TX (BIC 1)

ALARM (BIC 2)

ReTX (BIC 2)

DETECT (BIC 3)

TX (BIC 1)

ALARM (BIC 2)

ReTX (BIC 2)

DETECT (BIC 3)


DISCRETE BIDI Solution (1/2)

DESIGN:- Complex design (laser, very low analog signals, board design…)+ Allow flexibility (selection of components, optical power…)

COMPONENTS:• Discrete BIDI: Afonics (although lots similar)• TX circuit: MAX3263 (laser driver, Maxim)• RX circuit: SA5212 (TIA, Philips) + postamplifier (LT1016, Agilent board)

TX_TTL

RX_TTL


LED / LASERDRIVER

PREAMP(TIA)POSTAMP

ANALOG(VOLTAGE)

SIGNAL


Photodiode

WDM LIGHT

OPTICAL FIBER

DISCRETE BIDITX CIRCUIT

RX CIRCUIT


DISCRETE BIDI Solution (2/2) RESULTS:

+ Design fulfill the optical power budget rule • Transmitter output power: -27.5dB for “0” / -2.5dB for “1” Adjustable• Receiver sensibility: ~-30dB (R=0.5A/W it depends also on electronics)

- Must avoid receiver saturation

- Integrity of the signal (fall/rise time)

+ More power more margin of attenuation

+ Max. attenuation: 27.5dB (up to 50Km of fiber!!!!)

CONCLUSIONS:• SOLUTION WORKING• New board and more tests necessary

BUT STILL IN BUT STILL IN PROGRESSPROGRESS


OTHER SOLUTIONS S.I. Tech solution:

• Similar to Agilent solution (discrete components + analog to digital conversion)• Don’t allow transmission of DC signals

ONTi:• Chinese company with interests in working with CERN• Development for us• Good products and good price… but must be tested

Eva Calvo• Design: DC transmission, reliability… and radioactivity• Powerful transmitters (~1mW)• Discrete components + special electronic circuit: analog circuit + ECL• Tested and working

Cypress• Transmitter circuit = Agilent design• RX circuit with PECL postamplifier increases bandwidth


CONCLUSIONS MODULE solutions simple but not working well

2 solutions working:• ELED or Agilent solution simple• DISCRETE BIDI solution it uses only 1 fiber and allows more margin of attenuation, but complex and more tests necessary

“Detection and switch” working

No regeneration necessary detection only in the last module (should be tested)


FUTURE WORKS

Preparation of LHC simulation (using Agilent solution) with several modules in a loop

New board and more tests using DISCRETE BIDI solution

“Detection and switch” how and where (Core or Fiber Optic module)?

Conclusions: more tests, new boards, more components (attenuators)… more money and more time!!

Still a lot of work before taking the FINAL DECISSION


QUESTIONS?

jgimenoiwm-12/1/2004 fiber optic module 1 studies and development of a first fiber optic module...

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