rus
Issue #1/2016
A.R.Gayoso de los Santos, Z.Pavlova, A.Temnikov, A.Fedorov
Range of OEM Drivers for Laser Diode Power Supply
Range of OEM Drivers for Laser Diode Power Supply
Russian laser market is very different from the international market. The positions of lasers for scientific research and arms are much more serious. The experience of the laser product exit to the international market is described.
A
ccording to the research report published by MarketsandMarkets, the total market share of laser diodes is expected to be 11.94 billion US dollars by 2020, with the mean annual growth rate of about 13.0% during the period between 2015 and 2020. The increase of application scope of laser diodes in such areas as data communication and optical storage devices, industry, medicine, military and defense application scopes, instrument engineering etc. has been noted.
The current market trend stipulates the necessity to meet the needs of laser system manufacturers, first of all, and not the needs of scientific laboratories. The diagram Laser Focus World 2011, in which the lasers are divided by their application scopes, supplies only 5% of the total market of laser equipment to the market of research and development. Updated report of the magazine for 2015 does not give the percentage but we see approximately analogous ratio (Fig.1). Undoubtedly, the share of research and military industrial sector has grown in comparison with 2011 but it takes place not at the expense of change of market trends but at the expense of occurrence of several major defense projects, such as Common Infrared Countermeasure (CIRCM) program, in which Northrop Grumman company participates.
It should be noted that the Russian market is quite different than the international market. Laser positions for research and armament areas are more serious. When entering the international market, FEDAL faced these differences. It caused the company to set the primary task: necessity of compact built-in solution for the market of manufacturers of solid-state laser systems for industry, medicine and aircraft-borne applications. Besides compactness, the main specified requirements to the diode drivers include integration simplicity, reliability and high efficiency coefficient.
High requirements to compactness and reliability caused the transition to up-to-date circuit solutions with the switching frequencies of 0.5 to 2 MHz. It allowed decreasing the dimensions of filter elements and applying the new approaches in the algorithms of driver control.
Also, at the expense of multilayer printed circuit boards (PCB) use, the significant increase of assembly density and decrease of parasitic influence were achieved, and it favored the increase of product operation stability and optimization of thermal operation conditions due to the uniform heat distribution over the product volume. When designing the range of diode drivers, the product thermal calculation was performed in order to obtain the optimal heat removal (Fig.2). This solution is essential for the products with high power density.
The use of aluminum base for heat removal allows easy installation of the driver in air-cooled heater, water-cooled plate or wall of heat-capacious product frame providing the stable and reliable heat removal.
The driver range (see table) includes pulse (QCW, Pulse) (SF6015, SF6045) and continuous models (CW) (SF6035, SF6070, SF6100) (Fig.3).
When developing the pulse (QCW) drivers, the principle of partial discharge of the capacitive energy storage device was used; this method has proved itself in the power sources of SF3XX series. Use of this principle for the power supply of laser diodes is described in detail in the article "Power Sources of Solid-State Diode-Pumped Lasers", Photonics 1 (37) 2003.
Market of continuous (CW) drivers was new for the company, and therefore when developing the continuous drivers the needs of control group of customers were taken into account; as a result, the solutions concerning the unification increase were offered. The driver has analogous and digital control and supports the protocol of instruction exchange RS232 in two formats (hexadecimal and text). In the earliest possible timeframe, the company plans to develop SDK library. Delivery package contains the program developed in LabVIEW environment. The driver allows using wide input range.
The technological solutions of the company allowed achieving the high power density – 9 W per cubic centimeter. The drivers provide safe and durable operation of laser diode. Current ripples do not exceed 0.2% which prevents the untimely degradation of heterostructures of laser diodes. High accuracy of current setting allows correct selection of laser system operation conditions. Soft start, which provides the guaranteed absence of overshooting and low dI/dt (Fig.4), is implemented in the lasers. Selected speed of current buildup excludes the local overheating inside the crystal of laser diode, which considerably prolongs their service life and radiation stability.
A number of build-in protection devices, which ensure the safety of LD, is implemented in the drivers. Reverse diode protects the load from the occurrence of reverse current and excludes the occurrence of reverse voltage in the driver output. Built-in over current protection device ensures the safe operation of LD within the permissible current range. In case of actuation of over current protection device, the generation is ceased and output terminals are bypassed. Crowbar clamp allows securing the load even in case of the failure of driver components. Bi-threshold temperature protection device allows protecting the driver circuit from failure in case of insufficient cooling. When reaching the first temperature threshold, the signal is given and the flag warning about overheating is supplied. When reaching the second temperature threshold, the protection device is actuated and the driver is turned off.
As a result of performed operations, FEDAL has prepared the valid range of OEM drivers of laser diode power supply for the market launch. For the first time, the range was represented by European distributor – RedWave Labs at the exhibition Laser World of Photonics 2015. At the present moment, test deliveries are being performed. The drivers of SF6XXX series can become widely used in the laser complexes for material processing (marking, cutting, welding, piercing, soldering), medical equipment, measurement devices (range finders, lidars, spectrometers).
ccording to the research report published by MarketsandMarkets, the total market share of laser diodes is expected to be 11.94 billion US dollars by 2020, with the mean annual growth rate of about 13.0% during the period between 2015 and 2020. The increase of application scope of laser diodes in such areas as data communication and optical storage devices, industry, medicine, military and defense application scopes, instrument engineering etc. has been noted.
The current market trend stipulates the necessity to meet the needs of laser system manufacturers, first of all, and not the needs of scientific laboratories. The diagram Laser Focus World 2011, in which the lasers are divided by their application scopes, supplies only 5% of the total market of laser equipment to the market of research and development. Updated report of the magazine for 2015 does not give the percentage but we see approximately analogous ratio (Fig.1). Undoubtedly, the share of research and military industrial sector has grown in comparison with 2011 but it takes place not at the expense of change of market trends but at the expense of occurrence of several major defense projects, such as Common Infrared Countermeasure (CIRCM) program, in which Northrop Grumman company participates.
It should be noted that the Russian market is quite different than the international market. Laser positions for research and armament areas are more serious. When entering the international market, FEDAL faced these differences. It caused the company to set the primary task: necessity of compact built-in solution for the market of manufacturers of solid-state laser systems for industry, medicine and aircraft-borne applications. Besides compactness, the main specified requirements to the diode drivers include integration simplicity, reliability and high efficiency coefficient.
High requirements to compactness and reliability caused the transition to up-to-date circuit solutions with the switching frequencies of 0.5 to 2 MHz. It allowed decreasing the dimensions of filter elements and applying the new approaches in the algorithms of driver control.
Also, at the expense of multilayer printed circuit boards (PCB) use, the significant increase of assembly density and decrease of parasitic influence were achieved, and it favored the increase of product operation stability and optimization of thermal operation conditions due to the uniform heat distribution over the product volume. When designing the range of diode drivers, the product thermal calculation was performed in order to obtain the optimal heat removal (Fig.2). This solution is essential for the products with high power density.
The use of aluminum base for heat removal allows easy installation of the driver in air-cooled heater, water-cooled plate or wall of heat-capacious product frame providing the stable and reliable heat removal.
The driver range (see table) includes pulse (QCW, Pulse) (SF6015, SF6045) and continuous models (CW) (SF6035, SF6070, SF6100) (Fig.3).
When developing the pulse (QCW) drivers, the principle of partial discharge of the capacitive energy storage device was used; this method has proved itself in the power sources of SF3XX series. Use of this principle for the power supply of laser diodes is described in detail in the article "Power Sources of Solid-State Diode-Pumped Lasers", Photonics 1 (37) 2003.
Market of continuous (CW) drivers was new for the company, and therefore when developing the continuous drivers the needs of control group of customers were taken into account; as a result, the solutions concerning the unification increase were offered. The driver has analogous and digital control and supports the protocol of instruction exchange RS232 in two formats (hexadecimal and text). In the earliest possible timeframe, the company plans to develop SDK library. Delivery package contains the program developed in LabVIEW environment. The driver allows using wide input range.
The technological solutions of the company allowed achieving the high power density – 9 W per cubic centimeter. The drivers provide safe and durable operation of laser diode. Current ripples do not exceed 0.2% which prevents the untimely degradation of heterostructures of laser diodes. High accuracy of current setting allows correct selection of laser system operation conditions. Soft start, which provides the guaranteed absence of overshooting and low dI/dt (Fig.4), is implemented in the lasers. Selected speed of current buildup excludes the local overheating inside the crystal of laser diode, which considerably prolongs their service life and radiation stability.
A number of build-in protection devices, which ensure the safety of LD, is implemented in the drivers. Reverse diode protects the load from the occurrence of reverse current and excludes the occurrence of reverse voltage in the driver output. Built-in over current protection device ensures the safe operation of LD within the permissible current range. In case of actuation of over current protection device, the generation is ceased and output terminals are bypassed. Crowbar clamp allows securing the load even in case of the failure of driver components. Bi-threshold temperature protection device allows protecting the driver circuit from failure in case of insufficient cooling. When reaching the first temperature threshold, the signal is given and the flag warning about overheating is supplied. When reaching the second temperature threshold, the protection device is actuated and the driver is turned off.
As a result of performed operations, FEDAL has prepared the valid range of OEM drivers of laser diode power supply for the market launch. For the first time, the range was represented by European distributor – RedWave Labs at the exhibition Laser World of Photonics 2015. At the present moment, test deliveries are being performed. The drivers of SF6XXX series can become widely used in the laser complexes for material processing (marking, cutting, welding, piercing, soldering), medical equipment, measurement devices (range finders, lidars, spectrometers).
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