The research studies a new LED portable desk lamp with V-groove cells light guide plate (LGP). Such LGP enables light of edge LED to be transmitted from the LGP with high efficiency and uniformity to enter a lighting area. Here, the so called V-groove cell is a unit composed of multiple V-grooves we provided, which may regulate light effectively with appropriate design to implement the design goal of lighting. We analyze the impact of V-grooves parameters on LGP, and further, use portable DL as an example to search for suitable V-groove units, and acquire successfully a set of LGP with high efficiency, high illuminance uniformity, and low direct glare. Compared to the commercially available DL, the efficiency is increased by 1.4 times, and the illuminance distribution of target area is similar. Obviously, such microstructure unit composed of multiple V-groove microstructure (VGM) cells can implement design goal of LED portable DL with high efficiency.
A newly self-developed Broadband weighting function is presented to show the excellent results comparing with the Blackman and Hamming weighting function in applying to the waveguide structure of mismatched optical couplers for the demand of short-length, C+L-band, and low crosstalk. It is found that the coupler with the Broadband weighting function can reach the bandwidths between 1.360 to 1.700 μm with a coupling length of 2.5 mm and crosstalk of -35 dB. Obviously, the Broadband WF is suited in weighting the waveguide structure of a mismatched optical coupler to obtain a short coupling length, low crosstalk, and broad bandwidth.
We numerically investigate a new function modified from Hamming function to apply in weighting the waveguide
structure of a mismatched optical coupler with the characteristics of low crosstalk, short length, and broad C+L-band.
The full factorial design and beam propagation method are being used to seek the optimal structure parameters of
coupling waveguide. This modified Hamming weighting function (M-HWF) is proved to have the superior performances
to Hamming weighting function (HWF) in several ways. In theoretical computation, the M-HWF and HWF waveguides
have the coupling lengths of 11 mm and 16 mm, respectively at crosstalk of -40 dB and operating wavelength of 1.57
μm. After the numerical design of waveguide structure parameters, the M-HWF also obtain a shorter coupling length of
4.50 mm than coupling length of 5.90 mm of HWF at crosstalk of -40 dB and within the C+L-band (1.53~1.61 μm). The
M-HWF waveguide with the shortest coupling length of 4.5 mm can even reach a broader bandwidth between 1.50 and
A mismatched optical coupler with waveguide weighted by the Blackman function is numerically
investigated in the demand of short-length, C+L-band, low crosstalk, and process tolerance. Utilizing the full
factorial design, the structure parameters of coupling waveguide are obtained by beam propagation method. In
the condition of crosstalk of -33.5 dB, the mismatched optical coupler with proper selected waveguide structure
parameters is found to have a coupling length of 2.80 mm in the transmission wavelength ranges of C+L-band
(1.53~1.61 μm). Obviously, the selection and design of waveguide structure are very important to satisfy the
qualities of a mismatched optical coupler for the demand of short-length, bandwidth, and low-crosstalk.
The feasibility of a tunable optical fiber grating with a quasi-active and low cost actuator device fabricated by shape memory alloy is investigated. The driving force and displacement of the shape memory alloy actuator are measured. It is found that the SMA actuator with 0.3 mm diameter and 2 mm length driven by 7 V voltage after 5 sec can change the length of the fiber about 60μm, here the strain is about 3%. For the optical communication in the wavelength 1550nm regime, the tunable spectrum width is about 50nm. Therefore, the actuator can use to drive optical fiber grating, it will lead to change the fiber Bragg grating resonance wavelength. This device perhaps plays the key role of tunable optical filter or OADM.
The Raman effect influence on ultrashort pulse in optical fiber is investigated by using experimental data of delay response function. The frozen of the Raman effect is clarified by using nonlinear Schrodinger equation and finite difference time domain method. In Raman freezing region, a more stable soliton propagation is obtained when the initial power is enhanced.
Three new design waveguides for adiabatic directional full couplers are studied. We theoretically and numerically show that the performance of new full couplers is improved. Whe the length of the coupler is 4mm (the minimum local beat length is 2mm) at 1.57μm wavelength, the crosstalk is smaller than -35dB. For the length of the coupler is 4mm, the crosstalk is smaller than -20dB in the 1.5μm ~ 1.7μm range. For the length of the couplers is 7mm, we find that the crosstalk is smaller than -35dB in the 1.5μm ~ 1.7μm range. The same as the requirement of the maximum crosstalk, the corresponding wavelength is between 1.42μm to 1.7μm when the lenght of the couplers is 12mm.
We study the design of planar micro-grating and propose a new approach to fabricate planar micro-grating. By the basic grating diffractive theory (rigorous coupled wave theory), suitable and optimized structure (within our manufacturing capabilities) of grating for our application is found. The fabrication of planar micro-grating is demonstrated by Laser LIGA technology, using the instrument of KrF (248 nm) excimer laser system. The micro-grating with the continuous smooth profile and the pitch 2.5 ?m is shown.
In this paper, we demonstrate two configurations (A and B) distributed Raman fiber amplifier (RFA) with near flatten bandwidth of 40 nm in the 1530-1570 nm region. The wavelengths of Raman pumps are 1445 nm and 1470 nm. The dual-pumped Raman amplifier includes two optical isolators, and two 1550/14xx nm WDM couplers. Inside RFA there are dispersion compensation fiber (DCF) fiber integrated single-mode fiber (SMF). The chromatic dispersion of DCF and SMF are -85 and +17 ps/nm-km, respectively, while the attenuation of them are 0.43 and 0.19 dB/km, respectively. For the measurement of polarization dependent gain, the maximum gain of 24 dB is achieved with gain variation of 3.5 dB for configuration A. For gain equalization issue, the gain variation among the 1530-1570 nm is decreased from 8.3 dB to 2.4 dB when appropriately adjust the individual pump power for configuration B. One 10 Gb/s modulated signal is used to confirm the bit error rate performance of RFA. Small power penalty of 0.7 dB is observed.
This module combined the techniques of MEMS, near-field optics, fly head, and multiple beam. It organized the optical component and waveguide into a substrate. It integrated the multiple beam optical module for near-field high density recording, used the optics characteristic of the diffractive optical element, (DOE), generate multiple beams equally on the module, and reduce the spot size by using the near field optics. Simultaneously, quite a bit of information is recorded on the tracks of high density optical discs.