Abstract: Optical imaging systems are provided including a light source and a depolarizer. The light source is provided in a source arm of the optical imaging system. A depolarizer is coupled to the light source in the source arm of the optical imaging system and is configured to substantially depolarize the light from the light source. Related methods and controllers are also provided.

Abstract: A distributed arbitrary waveform generator (DAWG) synthesizes the target waveform using a series of narrow pulses generated by a number of pulse generators. To achieve this, it uses an input trigger signal to control all the pulse generators, each of which generates a narrow pulse (impulses) at a specific sample time, and then all the impulses are combined to generate the output waveform. The input trigger signal is distributed to each pulse generator by a trigger distribution network. Impulses generated by pulse generators can be tuned in both pulse amplitude and width, and the spacing between them can be tuned by the trigger distribution network. Therefore the waveforms generated are completely reconfigurable.

Abstract: An embodiment of the invention is directed to a pulse measuring system that measures a characteristic of an input pulse under test, particularly the pulse shape of a single-shot, nano-second duration, high shape-contrast optical or electrical pulse. An exemplary system includes a multi-stage, passive pulse replicator, wherein each successive stage introduces a fixed time delay to the input pulse under test, a repetitively-gated electronic sampling apparatus that acquires the pulse train including an entire waveform of each replica pulse, a processor that temporally aligns the replicated pulses, and an averager that temporally averages the replicated pulses to generate the pulse shape of the pulse under test. An embodiment of the invention is directed to a method for measuring an optical or an electrical pulse shape. The method includes the steps of passively replicating the pulse under test with a known time delay, temporally stacking the pulses, and temporally averaging the stacked pulses.

Abstract: An embodiment of the invention is directed to a dual-single-frequency fiber laser. A linear cavity formed by a short length of highly doped optical waveguide with distributed Bragg reflectors (DBRs) at respective ends, one of which is a polarization-maintaining PM-DBR, and a suitable pump source, provides orthogonally polarized dual-single-frequency laser emissions. Operating characteristics of the laser may be customized by appropriate design of the PM-DBR. Wavelength spacing between dual lasing wavelengths can be controlled via the birefringence parameters of the PM-DBR. Laser emission wavelengths may be controlled as a function of the period of the PM-DBR. Output power may be scaled upward by optimizing the PM-DBR reflectance and via pump power adjustment. Relaxation-oscillation effects (noise peaks) may be reduced by using a negative-feedback circuit on the pump laser.

Abstract: Methods of forming bulk optical elements, such as prisms, incorporating gratings are disclosed. Grating structures are formed by etching a uniform-thickness or generally planar substrate. Direct bonding, particularly chemical bonding, is then employed to bond the etched planar substrate to a bulk optical material without the use of adhesives or high temperature fusion.

Abstract: The invention is directed to metal-free grating for use in wavelength optical communications, and in particular to metal-free, reflective immersed diffraction gratings. The gratings of the invention area made of at least a first material 1 of refractive index n1 and a second material of refractive index n2. Materials 1 and 2 must obey the Expressions: (I) n1>n2, (II) n1>&lgr;/2L>n2 for single diffracted order at Littrow, and (III) n2/n1<Sin|&thgr;j|<1; wherein &lgr; is the wavelength of the light incident on the grating, &thgr;j represents any and all propagation angles of incident and diffracted light, and L is the grating period. The grating profile is located at the interface of material 1 and to material 2. In one embodiment, the grating profile is made from additional material 3 and 4 of refractive index n3 and n4, respectively, and is placed between materials 1 and 2. In another embodiment the grating is made from silicon.

Abstract: The invention is directed to metal-free grating for use in wavelength optical communications, and in particular to metal-free, reflective immersed diffraction gratings. The gratings of the invention area made of at least a first material 1 of refractive index n1 and a second material of refractive index n2. Materials 1 and 2 must obey the Expressions: (I) n1>n2, (II) n1>&lgr;/2L>n2 for single diffracted order at Littrow, and (III) n2/n1<Sin |&thgr;j|<1; wherein &lgr; is the wavelength of the light incident on the grating, &thgr;j represents any and all propagation angles of incident and diffracted light, and L is the grating period. The grating profile is located at the interface of material 1 and to material 2. In one embodiment, the grating profile is made from additional material 3 and 4 of refractive index n3 and n4, respectively, and is placed between materials 1 and 2. In another embodiment the grating is made from silicon.

Abstract: A high power fiber laser/amplifier is comprised of a multi-mode rare-earth-doped helical core disposed within a cylindrical inner cladding. The inner cladding is enclosed within an outer cladding whereby the core effectively produces single-mode operation with a circularly polarized near-diffraction-limited beam quality output when pump radiation is injected into the inner cladding.