SCIENTIFIC, NAUTICAL, SURVEYING, WEIGHING, MEASURING, SIGNALING, CHECKING, OPTICAL APPARATUS AND INSTRUMENTS, namely, FOR TELECOMMUNICATION, HIGH FREQUENCY AND REGULATION, NAMELY, HIGH FREQUENCY AMPLIFIERS, MULTIPLEXERS, DEMULTIPLEXERS, OPTICAL RECEIVERS, OPTICAL TRANSMITTERS, [ OPTICAL MODULATORS, ELECTRIC OPTICAL CONVERSION APPARATUS, ] NAMELY, AN OPTICAL TRANSMITTER CONSISTING OF AN ELECTRONIC AMPLIFIER DRIVING AN OPTICAL MODULATOR USED FOR THE CONVERSION OF ELECTRICAL TELECOMMUNICATION SIGNALS INTO LASER LIGHT SIGNALS SUITABLE FOR TRANSMISSION IN AN OPTICAL FIBER, BIT PATTERN GENERATORS WHICH PRODUCE ELECTRICAL DATA SIGNALS USED FOR TESTING HIGH-SPEED TELECOMMUNICATION SYSTEMS AND GENERATES RANDOM BIT SEQUENCES OF VARIOUS LENGTHS AND ADDITIONAL PATTERNS, ERROR ANALYZERS PARTICULARLY AN INSTRUMENT WHICH ANALYZES AN ELECTRICAL TELECOMMUNICATIONS SIGNAL TO CHECK IF ANY ERRORS CAN BE FOUND IN THE SIGNAL AT THE RECEIVER'S SITE, BIT ERROR RATE TEST SYSTEMS FOR THE GENERATION AND ANALYSIS OF TELECOMMUNICATION SIGNALS CONSISTING OF A BIT PATTERN GENERATOR AND ERROR ANALYZER, CLOCK GENERATORS WHICH PRODUCE AN ELECTRICAL CLOCK SIGNAL USED TO SYNCHRONIZE INCOMING DATA SIGNAL TO THE ERROR ANALYZER FOR ERROR DETECTION, [ SIGNAL SPLITTERS, ]FREQUENCY DOUBLERS, MONITOR- TEE'S PARTICULARLY AN ELECTRONIC CIRCUIT FOR MONITORING AN ELECTRICAL SIGNAL WITHOUT DISTURBING ITS INTEGRITIES IN MICROWAVE SYSTEMS, BIAS TEE'S PARTICULARLY AN ELECTRONIC CIRCUIT WHICH ADDS A CONSTANT VOLTAGE TO AN ELECTRICAL SIGNAL, [ MONOLITHIC MICROWAVE INTEGRATED CIRCUITS (MMIC), AND MODEMS; ] ELECTRIC APPARATUS AND INSTRUMENTS FOR HEAVY AND LIGHT CURRENT ENGINEERING, namely, FOR THE FIELDS OF CONDUCTION, TRANSFORMATION, STORAGE AND CONTROL, NAMELY, HIGH FREQUENCY AMPLIFIERS, MULTIPLEXERS, DEMULTIPLEXERS, OPTICAL RECEIVERS, OPTICAL TRANSMITTERS, [ OPTICAL MODULATORS, ] ELECTRIC-OPTICAL CONVERSION APPARATUS, NAMELY, AN OPTICAL TRANSMITTER CONSISTING OF AN ELECTRONIC AMPLIFIER DRIVING AN OPTICAL MODULATOR USED FOR THE CONVERSION OF ELECTRICAL TELECOMMUNICATION SIGNALS INTO LASER LIGHT SIGNALS SUITABLE FOR TRANSMISSION IN AN OPTICAL FIBER, BIT PATTERN GENERATORS WHICH PRODUCE ELECTRICAL DATA SIGNALS USED FOR TESTING HIGH-SPEED TELECOMMUNICATION SYSTEMS AND GENERATES RANDOM BIT SEQUENCES OF VARIOUS LENGTHS AND ADDITIONAL PATTERNS, ERROR ANALYZERS PARTICULARLY AN INSTRUMENT WHICH ANALYZES AN ELECTRICAL TELECOMMUNICATIONS SIGNAL TO CHECK IF ANY ERRORS CAN BE FOUND IN THE SIGNAL AT THE RECEIVER'S SITE, BIT ERROR RATE TEST SYSTEMS FOR THE GENERATION AND ANALYSIS OF TELECOMMUNICATION SIGNALS CONSISTING OF A BIT PATTERN GENERATOR AND ERROR ANALYZER, CLOCK GENERATORS WHICH PRODUCE AN ELECTRICAL CLOCK SIGNAL USED TO SYNCHRONIZE INCOMING DATA SIGNAL TO THE ERROR ANALYZER FOR ERROR DETECTION, SIGNAL SPLITTERS, FREQUENCY DOUBLERS, MONITOR-TEE'S PARTICULARLY AN ELECTRONIC CIRCUIT FOR MONITORING AN ELECTRICAL SIGNAL WITHOUT DISTURBING ITS INTEGRITIES IN MICROWAVE SYSTEMS, BIAS TEE'S PARTICULARLY AN ELECTRONIC CIRCUIT WHICH ADDS A CONSTANT VOLTAGE TO AN ELECTRICAL SIGNAL, MONOLITHIC MICROWAVE INTEGRATED CIRCUITS (MMIC) [, AND MODEMS ]