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public:optical_instruments 2010/07/19 12:21 public:optical_instruments 2017/05/03 21:53 current
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===== Lamps ===== ===== Lamps =====
-Lams Pare non coherent sources that usually emit light propagate to all directions. In photo physics research, lamps are used both for illumination and calibration.+Lamps are non coherent sources that usually emit light propagate to all directions. In photo physics research, lamps are used both for illumination and calibration.
===== Incandescent Lamps ===== ===== Incandescent Lamps =====
Incandescent lamps are the most common type of light source.  Typical incandescent lamps emit light by heating the filament and the emitted light continues broadband spectrum, which can be described by black body radiation. \\ Incandescent lamps are the most common type of light source.  Typical incandescent lamps emit light by heating the filament and the emitted light continues broadband spectrum, which can be described by black body radiation. \\
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{{  :research:optical_instruments:electronics_schematics_of_pulse_sampling_system.png?500  }} \\ {{  :research:optical_instruments:electronics_schematics_of_pulse_sampling_system.png?500  }} \\
-**Electronics schematic of a pulse sampling time-resolved fluorescence spectrometer \\ +**Electronics schematic of a pulse sampling time-resolved fluorescence spectrometer** \\
Time-resolved fluorescence spectrum of Rhodamin B and 9-cyanoanthracene mixture solution is shown here.  Rhodamin B has emission peak at 580nm and lifetime of 3.03ns while 9-cyanoanthracene has emission peak at 445nm and lifetime of 12ns.  \\ Time-resolved fluorescence spectrum of Rhodamin B and 9-cyanoanthracene mixture solution is shown here.  Rhodamin B has emission peak at 580nm and lifetime of 3.03ns while 9-cyanoanthracene has emission peak at 445nm and lifetime of 12ns.  \\
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====== Why Are Lasers Dangerous? ====== ====== Why Are Lasers Dangerous? ======
-The light sources and detectors used in optical instruments are potential sources of hazards to human if not properly operated.  These hazards primarily come from the optical radiation, high voltage electrical devices, and chemicals.  \\ +The light sources and detectors used in optical instruments are potential sources of hazards to human if not properly operated.  These hazards primarily come from the optical radiation, high voltage electrical devices, and chemicals.   
 +\\  
===== Laser and Light Radiation Safety ===== ===== Laser and Light Radiation Safety =====
Optical radiation hazards from the Sun light and high intensity lamps to human have long been discovered since their use in scientific research.  They had not been systematically studied, however, before the invention of laser in the 1960s.  Comparing with other light sources, the collimated beam of laser is capable of concentrating light energy in a tiny volume and short period of time.  In another word, low energy lasers light can have very high irradiance, which is defined as the amount of energy per unit volume and time.  \\ \\ Optical radiation hazards from the Sun light and high intensity lamps to human have long been discovered since their use in scientific research.  They had not been systematically studied, however, before the invention of laser in the 1960s.  Comparing with other light sources, the collimated beam of laser is capable of concentrating light energy in a tiny volume and short period of time.  In another word, low energy lasers light can have very high irradiance, which is defined as the amount of energy per unit volume and time.  \\ \\
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  * Avoid direct exposure of UV light to skin.  Studies have shown that excess UV light may cause skin cancers.    * Avoid direct exposure of UV light to skin.  Studies have shown that excess UV light may cause skin cancers. 
\\ \\
- 
===== Electrical Safety ===== ===== Electrical Safety =====
-Except for LED and semiconductor diode lasers, most of the laser systems have high voltage power supplies.  Some gas discharge lamps and detector systems such as PMT and intensifiers for CCD or streak cameras also have electrical system with line voltage exceeding tens of thousands of volts.  In addition, high energy pulsed laser systems have capacitors charged to several kilovolts with associated energy of hundreds of joules.  These high voltages and energies constitute potentially lethal shock hazards.  Although most of the complete commercial systems come in enclosed cases that provide some form of protection, most of bench top systems used in research laboratories require periodically maintenance that access to open circuit is needed.  Working with the large capacitor banks and very high voltage devices in light sources and detectors requires special attention.  Carelessly working around these high voltage electrical devices has the potential of causing severe electrical shock or even possibly result in electrocution.  Strict adherence to electrical guidelines and instrument manuals is the key to prevent accidents.  Some simple guidelines are listed here:  \\  +Except for LED and semiconductor diode lasers, most of the laser systems have high voltage power supplies.  Some gas discharge lamps and detector systems such as PMT and intensifiers for CCD or streak cameras also have electrical system with line voltage exceeding tens of thousands of volts.  In addition, high energy pulsed laser systems have capacitors charged to several kilovolts with associated energy of hundreds of joules.  These high voltages and energies constitute potentially lethal shock hazards.  Although most of the complete commercial systems come in enclosed cases that provide some form of protection, most of bench top systems used in research laboratories require periodically maintenance that access to open circuit is needed.  Working with the large capacitor banks and very high voltage devices in light sources and detectors requires special attention.  Carelessly working around these high voltage electrical devices has the potential of causing severe electrical shock or even possibly result in electrocution.  Strict adherence to electrical guidelines and instrument manuals is the key to prevent accidents.  \\ 
-1. Carefully read the operating and maintenance manual supplied by the manufacture.  Be familiar with which components have the potential to cause electrical hazards.  \\  + 
-2. Use only one hand for any manipulation of circuits whenever possible.  \\  +Some simple guidelines are 
-3. Work in a dry environment. \\  +   * Carefully read the operating and maintenance manual supplied by the manufacture.  Be familiar with which components have the potential to cause electrical hazards.  \\  
-4. Before any work, ground the whole circuit and use a portable multi-meter check the voltage. \\ +   * Use only one hand for any manipulation of circuits whenever possible.  \\  
 +   * Work in a dry environment. \\  
 +   * Before any work, ground the whole circuit and use a portable multi-meter check the voltage.  
 +\\  
===== Chemical Safety ===== ===== Chemical Safety =====
Many gas lasers and dye laser systems also contain highly toxic chemicals, which are also fire hazards in many cases.  Proper face masks and skin protection should be worn during maintenance procedures.  In some particular types of laser systems, respiratory devices should also have been used.  \\ \\ Many gas lasers and dye laser systems also contain highly toxic chemicals, which are also fire hazards in many cases.  Proper face masks and skin protection should be worn during maintenance procedures.  In some particular types of laser systems, respiratory devices should also have been used.  \\ \\

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